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1

Benzaldehyde Thiosemicarbazone Derived from Limonene Complexed with Copper Induced Mitochondrial Dysfunction in Leishmania amazonensis  

PubMed Central

Background Leishmaniasis is a major health problem that affects more than 12 million people. Treatment presents several problems, including high toxicity and many adverse effects, leading to the discontinuation of treatment and emergence of resistant strains. Methodology/Principal Findings We evaluated the in vitro antileishmanial activity of benzaldehyde thiosemicarbazone derived from limonene complexed with copper, termed BenzCo, against Leishmania amazonensis. BenzCo inhibited the growth of the promastigote and axenic amastigote forms, with IC50 concentrations of 3.8 and 9.5 µM, respectively, with 72 h of incubation. Intracellular amastigotes were inhibited by the compound, with an IC50 of 10.7 µM. BenzCo altered the shape, size, and ultrastructure of the parasites. Mitochondrial membrane depolarization was observed in protozoa treated with BenzCo but caused no alterations in the plasma membrane. Additionally, BenzCo induced lipoperoxidation and the production of mitochondrial superoxide anion radicals in promastigotes and axenic amastigotes of Leishmania amazonensis. Conclusion/Significance Our studies indicated that the antileishmania activity of BenzCo might be associated with mitochondrial dysfunction and oxidative damage, leading to parasite death.

Britta, Elizandra Aparecida; Barbosa Silva, Ana Paula; Ueda-Nakamura, Tania; Dias-Filho, Benedito Prado; Silva, Cleuza Conceicao; Sernaglia, Rosana Lazara; Nakamura, Celso Vataru

2012-01-01

2

3D-QSAR and molecular docking studies of benzaldehyde thiosemicarbazone, benzaldehyde, benzoic acid, and their derivatives as phenoloxidase inhibitors  

Microsoft Academic Search

Phenoloxidase (PO), also known as tyrosinase, is a key enzyme in insect development, responsible for catalyzing the hydroxylation of tyrosine into o-diphenols and the oxidation of o-diphenols into o-quinones. Inhibition of PO may provide a basis for novel environmentally friendly insecticides. In the present study, we determined the inhibitory activities and IC50 values of 57 compounds belonging to the benzaldehyde

Chao-Bin Xue; Li Zhang; Wan-Chun Luo; Xian-Ye Xie; Lin Jiang; Ting Xiao

2007-01-01

3

Synthesis, Characterization, and In Vitro Cytotoxic Activities of Benzaldehyde Thiosemicarbazone Derivatives and Their Palladium (II) and Platinum (II) Complexes against Various Human Tumor Cell Lines  

PubMed Central

The palladium (II) bis-chelate Pd (L1?3)2 and platinum (II) tetranuclear Pt4(L4)4 complexes of benzaldehyde thiosemicarbazone derivatives have been synthesized, and characterized by elemental analysis and IR, FAB(+)-mass and NMR (1H, 13C) spectroscopy. The complex Pd(L2)2 [HL2 = m-CN-benzaldehyde thiosemicarbazone] shows a square-planar geometry with two deprotonated ligands (L) coordinated to PdII through the nitrogen and sulphur atoms in a transarrangement, while the complex Pt4(L4)4 [HL4 = 4-phenyl-1-benzaldehyde thiosemicarbazone] has a tetranuclear geometry with four tridentate ligands coordinated to four PtII ions through the carbon (aromatic ring), nitrogen, and sulphur atoms where the ligands are deprotonated at the NH group. The in vitro antitumor activity of the ligands and their complexes was determined against different human tumor cell lines, which revealed that the palladium (II) and platinum (II) complexes are more cytotoxic than their ligands with IC50 values at the range of 0.07–3.67 ?M. The tetranuclear complex Pt4(L4)4, with the phenyl group in the terminal amine of the ligand, showed higher antiproliferative activity (CI50 = 0.07–0.12 ?M) than the other tested palladium (II) complexes.

Hernandeza, Wilfredo; Paz, Juan; Vaisberg, Abraham; Spodine, Evgenia; Richter, Rainer; Beyer, Lothar

2008-01-01

4

Simultaneous Determination of Cobalt(II) and Nickel(II) by Fourth-Order Derivative Spectrophotometric Method Using 2-Hydroxy-3-Methoxy Benzaldehyde Thiosemicarbazone  

PubMed Central

A simple and new simultaneous fourth derivative spectrophotometric method is proposed for the analysis of a two-component system containing cobalt(II) and nickel(II) without separation using 2-hydroxy-3-methoxy benzaldehyde thiosemicarbazone (HMBATSC) as a chromophoric reagent. The reagent reacts with cobalt(II) and nickel(II) at pH 6.0, forming soluble brown and yellow colored species, respectively. Cobalt(II) and nickel(II) present in themixture are simultaneously determined without solving the simultaneous equations bymeasuring the fourth derivative amplitudes at 468.5 nm and 474.5 nm, respectively. The derivative amplitudes obey Beer's law at 468.5 nm and 474.5 nm for Co(II) and Ni(II) in the range 0.059–3.299 ?g mL?1 and 0.058–3.285 ?g mL?1 respectively. A large number of foreign ions do not interfere in the present method. The present simultaneous method is used for the determination of micro amounts of cobalt in biological samples, nickel in plant samples, and in some alloy steels and soil sample.

Kumar, A. Praveen; Reddy, P. Raveendra; Reddy, V. Krishna

2007-01-01

5

Synthesis, Structure and Antioxidant Activity of (Tetra-O-acetyl-?-D-galactopyranosyl)thiosemicarbazones of Substituted Benzaldehydes  

PubMed Central

Some new substituted benzaldehyde (2,3,4,6-tetra-O-acetyl-?-D-galactopyranosyl) thiosemicarbazones were synthesised by reaction of 2,3,4,6-tetra-O-acetyl-?-D-galactopyranosyl thiosemicarbazide and different substituted benzaldehydes. The reaction was performed using conventional and microwave-assisted heating methods. The structures of thiosemicarbazones were confirmed by spectroscopic (IR, 1 H NMR, 13 C NMR and MS) method. The antioxidant activity of these thiosemicarbazones was evaluated, in vitro and in vivo, and it's shown that some of these compounds had significant antioxidant activity.

Thanh, Nguyen D.; Hoai, Le T.

2012-01-01

6

Structural, thermal and optical characterization of an organic NLO material—Benzaldehyde thiosemicarbazone monohydrate single crystals  

NASA Astrophysics Data System (ADS)

Single crystals of the organic NLO material, benzaldehyde thiosemicarbazone (BTSC) monohydrate, were grown by slow evaporation method. Solubility of BTSC monohydrate was determined in ethanol at different temperatures. The grown crystals were characterized by single crystal X-ray diffraction analysis to determine the cell parameters and by FT-IR technique to study the presence of the functional groups. Thermogravimetric and differential thermal analyses reveal the thermal stability of the crystal. UV-vis-NIR spectrum shows excellent transmission in the region of 200-1100 nm. Theoretical calculations were carried out to determine the linear optical constants such as extinction coefficient and refractive index. Further the optical nonlinearities of BTSC have been investigated by Z-scan technique with He-Ne laser radiation of wavelength 632.8 nm. Mechanical properties of the grown crystal were studied using Vickers microhardness tester. Second harmonic generation efficiency of the powdered BTSC monohydrate was tested using Nd:YAG laser and it is found to be ˜5.3 times that of potassium dihydrogen orthophosphate.

Santhakumari, R.; Ramamurthi, K.

2011-02-01

7

Structural studies and investigation on the activity of imidazole-derived thiosemicarbazones and hydrazones against crop-related fungi.  

PubMed

New imidazole derived thiosemicarbazones and hydrazones were prepared by condensation of 4(5)-imidazole carboxaldehyde, 4-(1H-imidazole-1-yl)benzaldehyde and 4-(1H-imidazole-1-yl)acetophenone with a thiosemicarbazide or hydrazide. All compounds were characterized by quantitative elemental analysis, IR and NMR techniques. Eight structures were determined by single crystal X-ray diffraction. The antifungal activities of the compounds were evaluated. None of the compounds exhibited significant activity against Aspergillus flavus and Candida albicans, while 4(5)-imidazolecarboxaldehyde thiosemicarbazone (ImT) and 4-(1H-imidazole-1-yl)benzaldehyde thiosemicabazone (4ImBzT) were highly and selectively active against Cladosporium cladosporioides. 4(5)-Imidazolecarboxaldehyde benzoyl hydrazone (4(5)ImPh), 4(5)-imidazolecarboxaldehyde-para-chlorobenzoyl hydrazone (4(5)ImpClPh), 4(5)-imidazolecarboxaldehyde-para-nitrobenzoyl hydrazone (4(5)ImpNO2Ph), 4-(imidazole-1-yl)acetophenone-para-chloro-benzoyl hydrazone (4ImAcpClPh) and 4-(imidazole-1-yl)acetophenone-para-nitro-benzoylhydrazone (4ImAcpNO2Ph) were highly active against Candida glabrata. 4(5)ImpClPh and 4(5)ImpNO2Ph were very effective against C. cladosporioides. In many cases, activity was superior to that of the reference compound nystatin. PMID:24129274

Reis, Débora C; Despaigne, Angel A Recio; Da Silva, Jeferson G; Silva, Nayane F; Vilela, Camila F; Mendes, Isolda C; Takahashi, Jacqueline A; Beraldo, Heloisa

2013-01-01

8

Hydrogen bonds and antiviral activity of benzaldehyde derivatives  

NASA Astrophysics Data System (ADS)

We have obtained the Fourier transform IR spectra of solutions of benzaldehyde derivatives having different antiviral activities against a herpes virus. We observe a correlation between the presence of hydrogen bonds in the benzaldehyde molecules and the appearance of antiviral properties in the compounds. For compounds having antiviral activity, we have obtained spectral data suggesting the existence of hydrogen bonds of the type C=O???H-O and O-H???O in the molecules. When the hydrogen atom in the hydroxyl groups are replaced by a methyl group, no intramolecular hydrogen bonds are formed and the compounds lose their antiviral activity.

Tolstorozhev, G. B.; Skornyakov, I. V.; Belkov, M. V.; Shadyro, O. I.; Brinkevich, S. D.; Samovich, S. N.

2012-09-01

9

Synthesis, antimicrobial and anticancer activity of new thiosemicarbazone derivatives.  

PubMed

Thiosemicarbazones of p-aminobenzoic acid (PABA) were synthesized and tested for their antimicrobial and anticancer activity. Hydroxamate derivatives 4a-4l were found to have better antimicrobial and anticancer activity than their acid counterpart. Compound 4d was found to have good antimicrobial activity against Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Vibrio cholerae, and Bacillus subtilis with IC(50) value of about 1 µM. Compound 4f showed potent antifungal activity against Candida albicans (IC(50) ?= 1.29 µM) and compound 4h showed potent anticancer activity (IC(50) ?= 0.07 µM). PMID:21290424

Kulandaivelu, Umasankar; Padmini, Valisakka Gari; Suneetha, Kyatham; Shireesha, Boyapati; Vidyasagar, Jannu Vincent; Rao, Tadikonda Rama; K N, Jayaveera; Basu, Arijit; Jayaprakash, Venkatesan

2011-02-01

10

The antimicrobial activity of lapachol and its thiosemicarbazone and semicarbazone derivatives  

PubMed Central

Lapachol was chemically modified to obtain its thiosemicarbazone and semicarbazone derivatives. These compounds were tested for antimicrobial activity against several bacteria and fungi by the broth microdilution method. The thiosemicarbazone and semicarbazone derivatives of lapachol exhibited antimicrobial activity against the bacteria Enterococcus faecalis and Staphylococcus aureus with minimal inhibitory concentrations (MICs) of 0.05 and 0.10 µmol/mL, respectively. The thiosemicarbazone and semicarbazone derivatives were also active against the pathogenic yeast Cryptococcus gattii (MICs of 0.10 and 0.20 µmol/mL, respectively). In addition, the lapachol thiosemicarbazone derivative was active against 11 clinical isolates of Paracoccidioides brasiliensis, with MICs ranging from 0.01-0.10 µmol/mL. The lapachol-derived thiosemicarbazone was not cytotoxic to normal cells at the concentrations that were active against fungi and bacteria. We synthesised, for the first time, thiosemicarbazone and semicarbazone derivatives of lapachol. The MICs for the lapachol-derived thiosemicarbazone against S. aureus, E. faecalis, C. gattii and several isolates of P. brasiliensis indicated that this compound has the potential to be developed into novel drugs to treat infections caused these microbes.

Souza, Marina Azevedo; Johann, Susana; Lima, Luciana Alves Rodrigues dos Santos; Campos, Fernanda Fraga; Mendes, Isolda Castro; Beraldo, Heloisa; de Souza-Fagundes, Elaine Maria; Cisalpino, Patricia Silva; Rosa, Carlos Augusto; Alves, Tania Maria de Almeida; de Sa, Nivea Pereira; Zani, Carlos Leomar

2013-01-01

11

Synthesis of novel highly functionalized 4-thiazolidinone derivatives from 4-phenyl-3-thiosemicarbazones.  

PubMed

We present herein the synthesis in good yields of two series of highly functionalized thiazolidinone derivatives from the reactions of various 4-phenyl-3-thio-semicarbazones with ethyl 2-bromoacetate and diethyl acetylenedicarboxylate, respectively. PMID:24619352

Benmohammed, Abdelmadjid; Khoumeri, Omar; Djafri, Ayada; Terme, Thierry; Vanelle, Patrice

2014-01-01

12

A rapid extractive spectrophotometric determination of copper(II) in environmental samples, alloys, complexes and pharmaceutical samples using 4-[N,N(dimethyl)amino]benzaldehyde thiosemicarbazone.  

PubMed

4-[N,N-(Dimethyl)amino]benzaldehyde thiosemicarbazone (DMABT) is proposed as an analytical reagent for the extractive spectrophotometric determination of copper(II). DMABT forms yellow colored complex with copper(II) in the pH range 4.4-5.4. Beer's law is obeyed in the concentration range up to 4.7 ?g mL(-1). The optimum concentration range for minimum photometric error as determined by Ringbom plot method is 1.2-3.8 ?g mL(-1). The yellowish Cu(II)-DMABT complex shows a maximum absorbance at 420 nm, with molar absorptivity of 1.72 × 10(4)dm(3) mol(-1) cm(-1) and Sandell's sensitivity of the complex obtained from Beer's data is 0.0036 ?g cm(-2). The composition of the Cu(II)-DMABT complex is found to be 1:2 (M/L). The interference of various cations and anions in the method were studied. Thus the method can be employed for the determination of trace amount of copper(II) in water, alloys and other natural samples of significant importance. PMID:20607390

Karthikeyan, J; Naik, P Parameshwara; Shetty, A Nityananda

2011-05-01

13

Synthesis and antitumor activity of amino derivatives of pyridine-2-carboxaldehyde thiosemicarbazone.  

PubMed

Various substituted pyridine-2-carboxaldehyde thiosemicarbazones (12 compounds) have been synthesized and evaluated for antineoplastic activity in mice bearing the L1210 leukemia. Oxidation of 3-nitro-2-picoline,5-nitro-2-picoline,3-nitro-2,4-lutidine, and 5-nitro-2,4-lutidine with selenium dioxide was employed to generate the corresponding pyridine-2-carboxaldehydes, which were then converted to cyclic ethylene acetals and subsequently reduced to amino and hydroxyamino derivatives by catalytic hydrogenation. Condensation of nitro aldehydes and acetals with thiosemicarbazide afforded the respective thiosemicarbazones. Acetylation of the amino acetals and alkylsulfonation of the 5-amino acetal, followed by condensation with thiosemicarbazide was employed to yield amide thiosemicarbazones. The most active compounds synthesized were 3-aminopyridine-2-carboxaldehyde thiosemicarbazone and 3-amino-4-methylpyridine-2-carboxaldehyde thiosemicarbazone which produced against the L1210 leukemia, % T/C values of 246 and 255, and 40% 60-day long-term survivors at two daily doses of 40 mg/kg and 10 mg/kg, respectively, for six consecutive days. PMID:1433178

Liu, M C; Lin, T S; Sartorelli, A C

1992-10-01

14

Novel heterocyclic thiosemicarbazones derivatives as colorimetric and ``turn on'' fluorescent sensors for fluoride anion sensing employing hydrogen bonding  

NASA Astrophysics Data System (ADS)

Two novel heterocyclic thiosemicarbazone derivatives have been synthesized, and characterized, by means of spectroscopic and single crystal X-ray diffraction methods. Their chromophoric-fluorogenic response towards anions in competing solvent dimethyl sulfoxide (DMSO) was studied. The receptor shows selective recognition towards fluoride anion. The binding affinity of the receptors with fluoride anion was calculated using UV-visible and fluorescence spectroscopic techniques.

Ashok Kumar, S. L.; Saravana Kumar, M.; Sreeja, P. B.; Sreekanth, A.

2013-09-01

15

IR spectra of benzaldehyde and its derivatives in different aggregate states  

NASA Astrophysics Data System (ADS)

We have measured the IR Fourier-transform spectra of biologically active benzaldehyde and its derivatives in the gas and liquid phases. For compounds of this class, the role played by C=O, OH, and CH groups in intra- and intermolecular has been analyzed. We have revealed spectral features that characterize the participation of C=O groups of unsubstituted benzaldehyde molecules in the occurrence of intermolecular hydrogen bonds C=O...H-C with the formation of molecular dimers of different types. For 2-hydroxybenzaldehyde molecules, spectral data have been obtained that are indicative of the occurrence of intramolecular hydrogen bonds of the C=O...H-C type in solutions. In 2-methoxybenzaldehyde molecules, no intramolecular hydrogen bonds have been observed.

Tolstorozhev, G. B.; Skornyakov, I. V.; Bel'kov, M. V.; Shadyro, O. I.; Brinkevich, S. D.; Samovich, S. N.

2012-08-01

16

Synthesis of isatin thiosemicarbazones derivatives: In vitro anti-cancer, DNA binding and cleavage activities  

NASA Astrophysics Data System (ADS)

New derivatives of thiosemicarbazone Schiff base with isatin moiety were synthesized L1-L6. The structures of these compounds were characterized based on the spectroscopic techniques. Compound L6 was further characterized by XRD single crystal. The interaction of these compounds with calf thymus (CT-DNA) exhibited high intrinsic binding constant (kb = 5.03-33.00 × 105 M-1) for L1-L3 and L5 and (6.14-9.47 × 104 M-1) for L4 and L6 which reflect intercalative activity of these compounds toward CT-DNA. This result was also confirmed by the viscosity data. The electrophoresis studies reveal the higher cleavage activity of L1-L3 than L4-L6. The in vitro anti-proliferative activity of these compounds against human colon cancer cell line (HCT 116) revealed that the synthesized compounds (L3, L6 and L2) exhibited good anticancer potency.

Ali, Amna Qasem; Teoh, Siang Guan; Salhin, Abdussalam; Eltayeb, Naser Eltaher; Khadeer Ahamed, Mohamed B.; Majid, A. M. S. Abdul

17

Synthesis of isatin thiosemicarbazones derivatives: in vitro anti-cancer, DNA binding and cleavage activities.  

PubMed

New derivatives of thiosemicarbazone Schiff base with isatin moiety were synthesized L1-L6. The structures of these compounds were characterized based on the spectroscopic techniques. Compound L6 was further characterized by XRD single crystal. The interaction of these compounds with calf thymus (CT-DNA) exhibited high intrinsic binding constant (k(b)=5.03-33.00×10(5) M(-1)) for L1-L3 and L5 and (6.14-9.47×10(4) M(-1)) for L4 and L6 which reflect intercalative activity of these compounds toward CT-DNA. This result was also confirmed by the viscosity data. The electrophoresis studies reveal the higher cleavage activity of L1-L3 than L4-L6. The in vitro anti-proliferative activity of these compounds against human colon cancer cell line (HCT 116) revealed that the synthesized compounds (L3, L6 and L2) exhibited good anticancer potency. PMID:24607427

Ali, Amna Qasem; Teoh, Siang Guan; Salhin, Abdussalam; Eltayeb, Naser Eltaher; Khadeer Ahamed, Mohamed B; Abdul Majid, A M S

2014-05-01

18

Efficient syntheses of thiadiazoline and thiadiazole derivatives by the cyclization of 3-aryl-4-formylsydnone thiosemicarbazones with acetic anhydride and ferric chloride  

Microsoft Academic Search

3-Aryl-4-formylsydnone 4?-phenylthiosemicarbazones 3a–d and 3-aryl-4-formylsydnone thiosemicarbazones 3e–h are effective precursors of sydnonyl-substituted heterocycles. The thiosemicarbazones 3a–d reacted with acetic anhydride (4a) to give 4-acetyl-2-phenylamino-5-(3-arylsydnon-4-yl)-4,5-dihydro-[1,3,4]thiadiazoles 5a–d and 4-acetyl-2-(N-phenylacetamido)-5-(3-arylsydnon-4-yl)-4,5-dihydro-[1,3,4]thiadiazoles 6a–d. However, under similar method, thiosemicarbazones 3e–h produced only 4-acetyl-2-acetamido-5-(3-arylsydnon-4-yl)-4,5-dihydro-[1,3,4]thiadiazoles 6e–h in high yield. The sydnonyl-substituted thiadiazole derivatives 7a–h were also obtained successfully by the cyclization of 3-aryl-4-formylsydnone thiosemicarbazones 3a–h with ferric chloride

Mei-Hsiu Shih; Cheng-Ling Wu

2005-01-01

19

Synthesis and characterization of some novel antimicrobial thiosemicarbazone O-carboxymethyl chitosan derivatives.  

PubMed

Three novel thiosemicarbazone O-carboxymethyl chitosan derivatives were obtained via a condensation reaction of thiosemicarbazide O-carboxymethyl chitosan with o-hydroxybenzaldehyde, p-methoxybenzaldehyde, and p- chlorobenzaldehyde respectively. Their structures were characterized by elemental analysis, FTIR, (13)C NMR and X-ray diffraction. The antimicrobial behaviors of the prepared derivatives against three types of bacteria Staphylococcus aureus (S. aureus, RCMBA 2004), Bacillus subtilis (B. subtilis, RCMBA 6005), and Escherichia coli (E. Coli, RCMBA 5003) and three crops-threatening pathogenic fungi Aspergillus fumigatus (A. fumigatus, RCMBA 06002), Geotrichum candidum (G. candidum, RCMB 05098), and Candida albicans (C. albicans, RCMB 05035) were investigated. The results indicated that the antibacterial and antifungal activities of the investigated derivatives are much higher than those of the parent O-carboxymethyl chitosan. They were more potent in case of Gram-positive bacteria than Gram-negative bacteria. The presence of electron withdrawing chlorine atom on the aryl moiety of the aldehyde portion improved greatly antimicrobial activity to be nearly equivalent to the used standard drugs. PMID:24211430

Mohamed, Nadia A; Mohamed, Riham R; Seoudi, Rania S

2014-02-01

20

Copper(II) complexes with 2-pyridineformamide-derived thiosemicarbazones: Spectral studies and toxicity against Artemia salina  

NASA Astrophysics Data System (ADS)

The copper(II) complexes [Cu(H2Am4DH)Cl 2] ( 1), [Cu(H2Am4Me)Cl 2] ( 2), [Cu(H2Am4Et)Cl 2] ( 3) and [Cu(2Am4Ph)Cl] ( 4) with 2-pyridineformamide thiosemicarbazone (H2Am4DH) and its N(4)-methyl (H2Am4Me), N(4)-ethyl (H2Am4Et) and N(4)-phenyl (H2Am4Ph) derivatives were studied by means of infrared and EPR spectral techniques. The crystal structure of 4 was determined. The studied compounds proved to be toxic to Artemia salina, suggesting that they could present cytotoxic activity against solid tumors. Among the free thiosemicarbazones H2Am4Ph presented higher toxicity than all other compounds, which showed comparable effects. In the case of complexes 2 and 3 toxicity is probably attributable to the complex as an entity or to a synergistic effect involving the thiosemicarbazone and copper. H2Am4Ph and complexes 2 and 3 revealed to be the most promising compounds as potential antineoplasic agents.

Ferraz, Karina O.; Wardell, Solange M. S. V.; Wardell, James L.; Louro, Sonia R. W.; Beraldo, Heloisa

2009-07-01

21

Benzaldehyde, 2-hydroxybenzoyl hydrazone derivatives as inhibitors of the corrosion of aluminium in hydrochloric acid.  

PubMed

The effect of benzaldehyde, 2-hydroxybenzoyl hydrazone derivatives on the corrosion of aluminium in hydrochloric acid has been investigated using thermometric and polarization techniques. The inhibitive efficiency ranking of these compounds from both techniques was found to be: 2>3>1>4. The inhibitors acted as mixed-type inhibitors but the cathode is more polarized. The relative inhibitive efficiency of these compounds has been explained on the basis of structure of the inhibitors and their mode of interaction at the surface. Results show that these additives are adsorbed on an aluminium surface according to the Langmuir isotherm. Polarization measurements indicated that the rate of corrosion of aluminium rapidly increases with temperature over the range 30-55 degrees C both in the absence and in the presence of inhibitors. Some thermodynamic data of the adsorption process are calculated and discussed. PMID:10823698

Fouda, A S; Gouda, M M; El-Rahman, S I

2000-05-01

22

Thiosemicarbazone derivate protects from AAPH and Cu 2+-induced LDL oxidation  

Microsoft Academic Search

AimsSeveral lines of evidence support the hypotheses that the oxidation of low density lipoprotein (LDL) may play a crucial role in the initiation and progression of atherosclerosis. Oxidative stress is one of the causes of the overproduction of reactive species that increase the formation of oxidized LDL. Thiosemicarbazones are compounds used in anticancer, antiviral and antifungal therapy; however, its redox

Rômulo Pillon Barcelos; Rafael de Lima Portella; Edovando José Flores da Rosa; Alexandra de Souza Fonseca; Leandro Bresolin; Vanessa Carratu; Félix Alexandre Antunes Soares; Nilda Vargas Barbosa

2011-01-01

23

N-methylisatin-beta-thiosemicarbazone derivative (SCH 16) is an inhibitor of Japanese encephalitis virus infection in vitro and in vivo  

Microsoft Academic Search

BACKGROUND: During the early and mid part of 20th century, several reports described the therapeutic effects of N-methylisatin-?-Thiosemicarbazone (MIBT) against pox viruses, Maloney leukemia viruses and recently against HIV. However, their ability to inhibit flavivirus replication has not been investigated. Hence the present study was designed to evaluate the antiviral activity of 14 MIBT derivatives against Flaviviruses that are prevalent

Liba Sebastian; Anita Desai; Madhusudana N Shampur; Yogeeswari Perumal; D Sriram; Ravi Vasanthapuram

2008-01-01

24

Influence of substituted benzaldehydes and their derivatives as inhibitors for hydrogen evolution in lead/acid batteries  

NASA Astrophysics Data System (ADS)

The influence of substituted benzaldehydes and their derivatives as inhibitors for hydrogen evolution on smooth and porous negative electrodes of the lead/acid system is investigated by cyclic voltammetric measurements. The experiments have been carried out with and without the presence of antimony. The effect of the inhibitors can be distinguished by a moderate and a strong inhibiting action. Use of these inhibitors in flooded lead/acid batteries can reduce water loss during cycling by 50%.

Dietz, H.; Hoogestraat, G.; Laibach, S.; von Borstel, D.; Wiesener, K.

25

Gold-catalyzed annulations of allenes with N-hydroxyanilines to form indole derivatives with benzaldehyde as a promoter.  

PubMed

Gold-catalyzed syntheses of 2,3-disubstituted indole derivatives from N-hydroxyanilines and allenes are described; these reactions require benzaldehyde as an additive to generate nitrones in situ. Our control experiments indicate that nitrones and water were indispensable in the reactions whereas N-hydroxyanilines alone were inactive nucleophiles. This synthetic method is compatible with allenes and N-hydroxyanilines with a reasonable range, further highlighting its synthetic utility. PMID:24395066

Kawade, Rahul Kisan; Huang, Po-Han; Karad, Somnath Narayan; Liu, Rai-Shung

2014-02-01

26

Chaetopyranin, a benzaldehyde derivative, and other related metabolites from Chaetomium globosum, an endophytic fungus derived from the marine red alga Polysiphonia urceolata.  

PubMed

Cultivation of the endophytic fungus Chaetomium globosum, which was isolated from the inner tissue of the marine red alga Polysiphonia urceolata, resulted in the isolation of chaetopyranin (1), a new benzaldehyde secondary metabolite. Ten known compounds were also isolated, including two benzaldehyde congeners, 2-(2',3-epoxy-1',3'-heptadienyl)-6-hydroxy-5-(3-methyl-2-butenyl)benzaldehyde (2) and isotetrahydroauroglaucin (3), two anthraquinone derivatives, erythroglaucin (4) and parietin (5), five asperentin derivatives including asperentin (6, also known as cladosporin), 5'-hydroxy-asperentin-8-methylether (7), asperentin-8-methyl ether (8), 4'-hydroxyasperentin (9), and 5'-hydroxyasperentin (10), and the prenylated diketopiperazine congener neoechinulin A (11). The structures of these compounds were determined on the basis of their spectroscopic data analysis (1H, 13C, 1H-1H COSY, HMQC, and HMBC NMR, as well as low- and high-resolution mass experiments). To our knowledge, compound 1 represents the first example of a 2H-benzopyran derivative of marine algal-derived fungi as well as of the fungal genus Chaetomium. Each isolate was tested for its DPPH (1,1-diphenyl-2-picrylhydrazyl) radical-scavenging property. Compounds 1-4 were found to have moderate activity. Chaetopyranin (1) also exhibited moderate to weak cytotoxic activity toward several tumor cell lines. PMID:17125234

Wang, Song; Li, Xiao-Ming; Teuscher, Franka; Li, Dong-Li; Diesel, Arnulf; Ebel, Rainer; Proksch, Peter; Wang, Bin-Gui

2006-11-01

27

Fe-catalyzed novel domino isomerization/cyclodehydration of substituted 2-[(indoline-3-ylidene)(methyl)]benzaldehyde derivatives: an efficient approach toward benzo[b]carbazole derivatives.  

PubMed

A new and efficient protocol to synthesize substituted benzo[b]carbazole derivatives has been demonstrated involving iron-catalyzed domino isomerization/cyclodehydration sequences from substituted 2-[(indoline-3-ylidene)(methyl)]benzaldehyde derivatives. The substrates could be easily made via Pd-catalyzed domino Heck-Suzuki coupling from 2-bromo-N-propargylanilide derivatives in high yields. Notably, the generality and efficiency of this two-stage domino strategy was further exemplified by the synthesis of a polycyclic benzofuran derivative. PMID:24742160

Paul, Kartick; Bera, Krishnendu; Jalal, Swapnadeep; Sarkar, Soumen; Jana, Umasish

2014-04-18

28

Oxidation of benzaldehydes to benzoic acid derivatives by three Desulfovibrio strains.  

PubMed Central

Desulfovibrio vulgaris Marburg, "Desulfovibrio simplex" XVI, and Desulfovibrio sp. strain MP47 used benzaldehydes such as vanillin, 3,4,5-trimethoxybenzaldehyde, protocatechualdehyde, syringaldehyde, p-anisaldehyde, p-hydroxybenzaldehyde, and 2-methoxybenzaldehyde as electron donors for sulfate reduction and carbon dioxide and/or components of yeast extract as carbon sources for cell synthesis. The aldehydes were oxidized to their corresponding benzoic acids. The three sulfate reducers oxidized up to 7 mM vanillin and up to 4 mM p-anisaldehyde. Higher concentrations of vanillin or p-anisaldehyde were toxic. In addition, pyridoxal hydrochloride and o-vanillin served as electron donors for sulfate reduction. Salicylaldehyde, pyridine-2-aldehyde, pyridine-4-aldehyde, and 4-hydroxy-3-methoxybenzylalcohol were not oxidized. No molecular hydrogen was detected in the gas phase. The oxidized aldehydes were not further degraded.

Zellner, G; Kneifel, H; Winter, J

1990-01-01

29

Structural and spectral studies of a 1- N(4)-substituted thiosemicarbazone derived from 2-hydroxy-1,4-naphthaquinone  

NASA Astrophysics Data System (ADS)

2-Hydroxy-1,4-naphthaquinone reacted with N(4)-ethylthiosemicarbazide in basic solution forms the 1-thiosemicarbazone. The crystal structure shows that the 2-hydroxy hydrogen is shifted to the remaining quinone oxygen resulting in the formation of a dimer due to intermolecular hydrogen bonding from each hydroxy group to the other molecule's quinone oxygen. Intramolecular hydrogen bonding occurs between the amide NH and the imine thiosemicarbazone moiety, as well as between the hydrazinic NH and the quinone oxygen. This new compound's IR, UV and 1H NMR spectra are included.

West, D. X.; Castiñeiras, A.; Bermejo, E.

2000-03-01

30

Synthesis and Characterization of some Transition Metal Complexes of Thiosemicarbazones Derived from 2?acetylpyrrole and 2?acetylfuran  

Microsoft Academic Search

Copper(II), nickel(II), palladium(II), platinum(II), and silver(I) complexes of 2?acetylpyrrole thiosemicarbazone (H2L) and copper(II), nickel(II), platinum(II) and zinc(II) complexes of 2?acetylfuran thiosemicarbazone (HL) have been prepared and characterized by conductance, electronic, infrared, magnetic and H NMR spectral measurements in addition to elemental and thermogravimetrical analyses. Square?planar structures are suggested for the H2L complexes of Cu(II), Ni(II), Pd(II) and Pt(II), whereas octahedral

Nabil S. Youssef; K. H. Hegab

2005-01-01

31

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

PubMed

Toxoplasma, which infects all eukaryotic cells, is considered to be a good system for the study of drug action and of the behavior of infected host cells. In the present study, we asked if thiosemicarbazone derivatives can be effective against tachyzoites and which morphological and ultrastructural features of host cells and parasites are associated with the destruction of Toxoplasma. The compounds were tested in infected Vero cell culture using concentration screens (0.1 to 20 mM). The final concentration of 1 mM was chosen for biological assay. The following results were obtained: 1) These new derivatives decreased T. gondii infection with an in vitro parasite IC50% of 0.2-0.7 mM, without a significant effect on host cells and the more efficient compounds were 2, 3 (thiosemicarbazone derivatives) and 4 (thiazolidinone derivative); 2) The main feature observed during parasite elimination was continuous morphological disorganization of the tachyzoite secretory system, progressive organelle vesiculation, and then complete disruption; 3) Ultrastructural assays also revealed that progressive vesiculation in the cytoplasm of treated parasites did not occur in the host cell; 4) Vesiculation inside the parasite resulted in death, but this feature occurred asynchronously in different intracellular tachyzoites; 5) The death and elimination of T. gondii was associated with features such as apoptosis-like stage, acidification and digestion of parasites into parasitophorous vacuoles. Our results suggest that these new chemical compounds are promising for the elimination of intracellular parasites by mainly affecting tachyzoite development at 1 mM concentration for 24 h of treatment. PMID:19893994

Carvalho, C S; Melo, E J T de; Tenório, R P; Góes, A J S

2010-02-01

32

Pestalols A-E, new alkenyl phenol and benzaldehyde derivatives from endophytic fungus Pestalotiopsis sp. AcBC2 isolated from the Chinese mangrove plant Aegiceras corniculatum.  

PubMed

Five alkenyl phenol and benzaldehyde derivatives, pestalols A-E (1-5), as well as seven known compounds (6-12), were isolated from endophytic fungus Pestalotiopsis sp. AcBC2 derived from the Chinese mangrove plant Aegiceras corniculatum. Their structures were determined by spectroscopic analyses. Compounds 2 and 3 showed cytotoxicity against a panel of 10 tumor cell lines. Compounds 1-5, 8, 9, 11, and 12 showed inhibitory activities against Influenza A virus subtype (H3N2) and Swine Flu (H1N1) viruses. Compound 2 also showed inhibitory activity against tuberculosis. PMID:24690916

Sun, Jian-Fan; Lin, Xiuping; Zhou, Xue-Feng; Wan, Junting; Zhang, Tianyu; Yang, Bin; Yang, Xian-Wen; Tu, Zhengchao; Liu, Yonghong

2014-06-01

33

Antioxidant, antimicrobial, and theoretical studies of the thiosemicarbazone derivative Schiff base 2-(2-imino-1-methylimidazolidin-4-ylidene)hydrazinecarbothioamide (IMHC)  

PubMed Central

Background Adverse antimicrobial activities of thiosemicarbazone (TSC) and Schiff base derivatives have widely been studied by using different kinds of microbes, in addition different methods were used to assay the antioxidant activities using DPPH, peroxids, or ntrosyl methods. However, there are no studies describing the synthesis of TSC derived from creatinine. Results In this study, 2-(2-imino-1-methylimidazolidin-4-ylidene)hydrazinecarbothioamide (IMHC) was synthesized by the reaction of creatinine with thiosemicarbazide. The novel molecule was characterized by FT-IR, UV-VIS, and NMR spectra in addition of the elemental analysis. The free radical scavenging ability of the IMHC was determined by it interaction with the stable-free radical 2,2"-diphenyl-1-picrylhydrazyl (or nitric oxide or hydrogen peroxide) and showed encouraging antioxidant activities. Density functional theory calculations of the IMHC performed using molecular structures with optimized geometries. Molecular orbital calculations provide a detailed description of the orbitals, including spatial characteristics, nodal patterns, and the contributions of individual atoms. Highest occupied molecular orbital-lowest unoccupied molecular orbital energies and structures are shown. Conclusions IMHC shows considerable antibacterial and antifungal activities. The free radical scavenging activity of synthesized compound was screened for in vitro antioxidant activity.

2012-01-01

34

Synthesis and Characterization of New Palladium(II) Thiosemicarbazone Complexes and Their Cytotoxic Activity against Various Human Tumor Cell Lines  

PubMed Central

The palladium(II) bis-chelate complexes of the type [Pd(TSC1-5)2] (6–10), with their corresponding ligands 4-phenyl-1-(acetone)-thiosemicarbazone, HTSC1 (1), 4-phenyl-1-(2?-chloro-benzaldehyde)-thiosemicarbazone, HTSC2 (2), 4-phenyl-1-(3?-hydroxy-benzaldehyde)-thiosemicarbazone, HTSC3 (3), 4-phenyl-1-(2?-naphthaldehyde)-thiosemicarbazone, HTSC4 (4), and 4-phenyl-1-(1?-nitro-2?-naphthaldehyde)-thiosemicarbazone, HTSC5 (5), were synthesized and characterized by elemental analysis and spectroscopic techniques (IR and 1H- and 13C-NMR). The molecular structure of HTSC3, HTSC4, and [Pd(TSC1)2] (6) have been determined by single crystal X-ray crystallography. Complex 6 shows a square planar geometry with two deprotonated ligands coordinated to PdII through the azomethine nitrogen and thione sulfur atoms in a cis arrangement. The in vitro cytotoxic activity measurements indicate that the palladium(II) complexes (IC50 = 0.01–9.87??M) exhibited higher antiproliferative activity than their free ligands (IC50 = 23.48–70.86 and >250??M) against different types of human tumor cell lines. Among all the studied palladium(II) complexes, the [Pd(TSC3)2] (8) complex exhibited high antitumor activity on the DU145 prostate carcinoma and K562 chronic myelogenous leukemia cells, with low values of the inhibitory concentration (0.01 and 0.02??M, resp.).

Hernandez, Wilfredo; Paz, Juan; Carrasco, Fernando; Spodine, Evgenia; Manzur, Jorge; Sieler, Joachim; Blaurock, Steffen; Beyer, Lothar

2013-01-01

35

Deuterium and Solvent Effects on Benzaldehyde Phosphorescence.  

National Technical Information Service (NTIS)

The phosphorescence lifetime and spectra of benzaldehyde, benzaldehyde-d1 and benzaldehyde-d6 have been measured in methylcyclohexane, EPA, and 85% H3PO4 glasses at 77K. The measurements are consistent with a triplet state assignement of triplet n, pi* in...

J. Simpson H. Offen

1970-01-01

36

Potential antitumor agents. 14. 4-Substituted 2-formylpyridine thiosemicarbazones.  

PubMed

A series of 4-substituted 2-formylpyridine thiosemicarbazones has been synthesized which contain a tertiary N at the 4 position. These materials were obtained by reacting 4-nitro-2-picoline N-oxide, either directly or after conversion to the corresponding 4-chloro derivative, with a variety of secondary amines. Rearrangement of the 4-substituted 2-picoline N-oxides with Ac2O yielded respective methyl acetates, which upon acid hydrolysis, MnO2 oxidation, and reaction with thiosemicarbazide resulted in the desired compounds. An alternate procedure which consisted of reacting 4-chloro-2-formylpyridine ethylene acetal with various amines, followed by hydrolysis and reaction with thiosemicarbazide, was also employed. Introduction of an alkyl group at the 3 position of the pyridine ring of 4-morpholino-2-formylpyridine thiosemicarbazone was achieved by utilizing 2,3-dimethyl-4-nitropyridine N-oxide; this material was converted to the corresponding 4-chloro derivative which was then subjected to nucleophilic substitution. 4-Morpholino-2-formylpyridine thiosemicarbazone was the most active antineoplastic agent of this series in mice bearing Sarcoma 180 ascites cells and was significantly superior to 5-hydroxy-2-formylpyridine thiosemicarbazone in this test system. PMID:994151

Agrawal, K C; Booth, B A; DeNuzzo, S; Sartorelli

1976-10-01

37

Cytotoxic activities of new iron(III) and nickel(II) chelates of some S -methyl-thiosemicarbazones on K562 and ECV304 cells  

Microsoft Academic Search

Summary  The S-methyl-thiosemicarbazones of the 2-hydroxy-R-benzaldehyde (R= H, 3-OH 3-OCH3 or 4-OCH3) reacted with the corresponding aldehydes in the presence of FeCl3 and NiCl2. New ONNO chelates of iron(III) and nickel(II) with hydroxy- or methoxy-substitued N\\u000a 1,N\\u000a 4-diarylidene-S-methyl-thiosemicarbazones were characterized by means of elemental analysis, conductivity and magnetic measurements, UV-Vis,\\u000a IR and 1H-NMR spectroscopies. Cytotoxic activities of the compounds were determined

Belk?s Atasever; Bahri Ülküseven; Tülay Bal-Demirci; Serap Erdem-Kuruca; Zeynep Solako?lu

2010-01-01

38

Synthesis, Spectral, and Biological Properties of Copper(II) Complexes of Thiosemicarbazones of Schiff Bases Derived from 4-Aminoantipyrine and Aromatic Aldehydes  

PubMed Central

We have synthesized a novel series of Schiff bases by condensation of 4-aminoantipyrine and various aromatic aldehydes followed by reaction with thiosemicarbazide. These thiosemicarbazones are potential ligands toward transition metal ions. The reaction of copper(II) salts with 4[N-(benzalidene)amino]antipyrinethiosemicarbazone (BAAPTS), 4[N-(4?-methoxybenzalidene) amino] antipyrinethiosemicarbozone (MBAAPTS), 4[N-(4?-dimethylamino benzalidene) amino] antipyrinethiosemicarbazone (DABAAPTS), and 4[N-(cinnamalidene) amino] antipyrinethiosemicarbazone (CAAPTS) resulted in the formation of solid complexes with the general composition CuX2 · (H2O)(L)(X = Cl, Br,NO3,NCS, or CH3COO; L = BAAPTS, MBAAPTS, DABAAPTS, or CAAPTS). These complexes were characterized through elemental analysis, molecular weight, electrical conductance, infrared, electronic spectra, and magnetic susceptibilities at room temperature. Copper(II) complexes with BAAPTS and MBAAPTS were screened for antibacterial and antifungal properties and have exhibited potential activity. Thermal stabilities of two representative complexes were also investigated.

Agarwal, Ram K.; Singh, Lakshman; Sharma, Deepak Kumar

2006-01-01

39

Microwave assisted synthesis, X-ray crystallography and DFT calculations of selected aromatic thiosemicarbazones  

NASA Astrophysics Data System (ADS)

Series of four benzaldehyde thiosemicarbazones has been synthesized under microwave irradiation and characterized structurally by means of infrared and NMR spectroscopies and mass spectrometry. Their crystal structures were determined by single crystal X-ray analysis followed by DFT calculations. Partial charges on the molecular surface and dipole moments of the structures were calculated. Crystal structures are stabilized by intramolecular hydrogen bonding and stacking interactions. Studied compounds are interesting as antiproliferative and antifungal agents acting through interactions with iron. Thus presented results may be useful in design new more active or specific structures.

Serda, Maciej; Ma?ecki, Jan G.; Mrozek-Wilczkiewicz, Anna; Musio?, Robert; Pola?ski, Jaros?aw

2013-04-01

40

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)

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.

Singh, Ajay K.; Pandey, O. P.; Sengupta, S. K.

2013-09-01

41

Stability of the Resistance to the Thiosemicarbazone Derived from 5,6-Dimethoxy-1-Indanone, a Non-Nucleoside Polymerase Inhibitor of Bovine Viral Diarrhea Virus  

PubMed Central

Bovine viral diarrhea virus (BVDV) is the prototype Pestivirus. BVDV infection is distributed worldwide and causes serious problems for the livestock industry. The thiosemicarbazone of 5,6-dimethoxy-1-indanone (TSC) is a non-nucleoside polymerase inhibitor (NNI) of BVDV. All TSC-resistant BVDV variants (BVDV-TSCr T1–5) present an N264D mutation in the NS5B gene (RdRp) whereas the variant BVDV-TSCr T1 also presents an NS5B A392E mutation. In the present study, we carried out twenty passages of BVDV-TSCr T1–5 in MDBK cells in the absence of TSC to evaluate the stability of the resistance. The viral populations obtained (BVDV R1–5) remained resistant to the antiviral compound and conserved the mutations in NS5B associated with this phenotype. Along the passages, BVDV R2, R3 and R5 presented a delay in the production of cytopathic effect that correlated with a decrease in cell apoptosis and intracellular accumulation of viral RNA. The complete genome sequences that encode for NS2 to NS5B, Npro and Erns were analyzed. Additional mutations were detected in the NS5B of BVDV R1, R3 and R4. In both BVDV R2 and R3, most of the mutations found were localized in NS5A, whereas in BVDV R5, the only mutation fixed was NS5A V177A. These results suggest that mutations in NS5A could alter BVDV cytopathogenicity. In conclusion, the stability of the resistance to TSC may be due to the fixation of different compensatory mutations in each BVDV-TSCr. During their replication in a TSC-free medium, some virus populations presented a kind of interaction with the host cell that resembled a persistent infection: decreased cytopathogenicity and viral genome synthesis. This is the first report on the stability of antiviral resistance and on the evolution of NNI-resistant BVDV variants. The results obtained for BVDV-TSCr could also be applied for other NNIs.

Castro, Eliana F.; Campos, Rodolfo H.; Cavallaro, Lucia V.

2014-01-01

42

Manganese(II) complexes of substituted di-2-pyridyl ketone thiosemicarbazones: structural and spectral studies.  

PubMed

The reaction between manganese(II) acetate and two substituted thiosemicarbazones derived from di-2-pyridyl ketone (HL) in 1:2 molar ratio produces new complexes of general formula [MnL2]. The thiosemicarbazone moiety in HL deprotonates and gets coordinated to Mn(II) through the azomethine nitrogen, one of the pyridyl nitrogens, and the thiolate sulfur in both the complexes. The crystal structure of [MnL2(1)] was established by single crystal X-ray diffraction and the compound crystallizes into a monoclinic lattice with P2(1)/c space group. Manganese(II) exists in a distorted octahedral geometry in the complexes. PMID:16098800

Philip, Varughese; Suni, V; Kurup, Maliyeckal R Prathapachandra; Nethaji, Munirathinam

2006-05-01

43

Trypanocidal and cytotoxic evaluation of synthesized thiosemicarbazones as potential drug leads against sleeping sickness.  

PubMed

Thiosemicarbazones have become one of the promising compounds as new clinical candidates due to their wide spectrum of pharmaceutical activities. The wide range of their biological activities depends generally on their related aldehyde or ketone groups. Here, we report the pharmacological activities of some thiosemicarbazones synthesized in this work. Benzophenone and derivatives were used with N(4)-phenyl-3-thiosemicarbazide to synthesize corresponding five thiosemicarbazones (1-5). Their structures were characterized by spectrometrical methods analysis IR, NMR (1)H & (13)C and MS. The compounds were then screened in vitro for their antiparasitic activity and toxicity on Trypanosoma brucei brucei and Artemia salina Leach respectively. The selectivity index of each compound was also determined. Four thiosemicarbazones such as 4, 2, 3 and 1 reveal interesting trypanocidal activities with their half inhibitory concentration (IC50) equal to 2.76, 2.83, 3.86 and 8.48 ?M respectively, while compound 5 (IC50 = 12.16 ?M) showed a moderate anti-trypanosomal activity on parasite. In toxicity test, except compound 1, which showed a half lethal concentration LC50 >281 ?M, the others exerted toxic effect on larvae with LC50 of 5.56, 13.62, 14.55 and 42.50 ?M respectively for thiosemicarbazones 4, 5, 3 and 2. In agreement to their selectivity index, which is greater than 1 (SI >1), these compounds clearly displayed significant selective pharmaceutical activities on the parasite tested. The thiosemicarbazones 2-5 that displayed significant anti-trypanosomal and cytoxicity activities are suggested to have anti-neoplastic and anti-cancer activities. PMID:24407605

Glinma, Bienvenu; Kpoviessi, Sika D S; Gbaguidi, Fernand A; Kapanda, Coco N; Bero, Joanne; Quetin-Leclercq, Joëlle; Moudachirou, Mansourou; Poupaert, Jacques; Accrombessi, Georges C; Gachomo, Emma W; Baba-Moussa, Lamine; Kotchoni, Simeon O

2014-03-01

44

Infrared Spectra and Hydrogen Bonds of Biologically Active Benzaldehydes  

NASA Astrophysics Data System (ADS)

IR-Fourier spectra of solutions and crystals of biologically active benzaldehyde derivatives were studied. Specific features of the formation of intra- and intermolecular hydrogen bonds were analyzed. Spectral signatures that characterized participation of the hydroxyl OH group and also the OCH3 and C=O groups in the formation of intramolecular hydrogen bonds of the three different types O-H···O-H, O-H···O-CH3, and O-H···O=C were revealed. Intramolecular hydrogen bonds of the types O-H···O-H and O-H···O-CH3 were absent for benzaldehyde derivatives in the crystal phase. Only hydroxyl and carbonyl groups participated in intermolecular interactions. This resulted in the formation of linear intermolecular dimers. Seven various configurations of the linear dimers were identified in solutions and crystals.

Tolstorozhev, G. B.; Skornyakov, I. V.; Belkov, M. V.; Shimko, A. N.; Shadyro, O. I.; Brinkevich, S. D.; Samovich, S. N.

2013-09-01

45

Structural and spectral studies of an iron(III) complex [Fe(Pranthas) 2][FeCl 4] derived from 2-acetylpyridine- N(4), N(4)-(butane-1, 4-diyl) thiosemicarbazone (HPranthas)  

Microsoft Academic Search

A novel iron(III) complex of 2-acetylpyridine N(4), N(4)-(butyl-1, 4-diyl) thiosemicarbazone (HPranthas), [Fe(Pranthas)2]FeCl4 was synthesized and physico-chemically characterized by means of partial elemental analysis, magnetic measurements (polycrystalline state), UV–Vis and IR spectroscopies. The presence of spin-paired iron(III) cation with dxz2dyz2dxy1 ground state is revealed by the EPR and Mössbauer spectral data. Structure of the free ligand HPranthas and the complex [Fe(Pranthas)2]FeCl4

A. Sreekanth; Hoong-Kun Fun; M. R. Prathapachandra Kurup

2005-01-01

46

Synthesis, cytotoxic activity and DNA-interaction studies of novel anthraquinone-thiosemicarbazones with tautomerizable methylene group.  

PubMed

A series of novel anthraquinone-thiosemicarbazone derivatives in a tautomerizable keto-imine form was synthesized and tested for their in vitro cytotoxic activity against human cancer cells (HeLa, MDA-MB-361, MDA-MB-453, K562, A549) and human normal MRC-5 cells. Several compounds efficiently inhibited cancer cell growth at micromolar concentrations, especially against K562 and HeLa cells. As determined by flow cytometric analysis, anthraquinone-thiosemicarbazone caused significant increase in the number of sub-G1 phase of HeLa cells and apoptosis in a concentration-dependent manner. Also, inhibition of caspase-3, -8, and -9 with specific caspase inhibitors reduced the apoptosis mediated by the tested compounds in HeLa cells. All anthraquinone-thiosemicarbazones exhibit calf thymus DNA-binding activity, but no cleavage of plasmid DNA was observed. PMID:23644206

Markovi?, Violeta; Jani?ijevi?, Ana; Stanojkovi?, Tatjana; Kolundžija, Branka; Sladi?, Dušan; Vuj?i?, Miroslava; Janovi?, Barbara; Joksovi?, Ljubinka; Djurdjevi?, Predrag T; Todorovi?, Nina; Trifunovi?, Snežana; Joksovi?, Milan D

2013-06-01

47

Health and Environmental Effects Profile for Benzaldehyde.  

National Technical Information Service (NTIS)

The Health and Environmental Effects Profile for benzaldehyde was prepared by the Office of Health and Environmental Assessment, Environmental Criteria and assessment Office, Cincinnati, OH for the Office of Solid Waste and Emergency Response to support l...

1985-01-01

48

Synthesis and antihyperglycemic activity of 2-(substituted phenyl)-3-{[4-(1-naphthyl)-1,3-thiazol-2-yl] amino}-4-oxo-1,3-thiazolidin-5-ylacetic acid derivatives.  

PubMed

The title compounds were prepared by brominating 1-acetylnaphthalene in chloroform followed by condensation with substituted benzaldehyde thiosemicarbazones using ethanol to get 4-naphthalen-1-yl-2-{2-[(substituted phenyl)methylidene]hydrazino}-1,3-thiazoles. These thiazole derivatives were then cyclized to title compounds by reacting with thiomalic acid in dioxane using ZnCl2. All the synthesized compounds were characterized on the basis of their IR, 1H NMR, and elemental analysis. The antihyperglycemic study was divided into two phases. Phase-I involved evaluation of blood glucose lowering ability of thiazolidinones in normal rats by sucrose-loaded model (SLM). Phase-II study included the evaluation of blood sugar by alloxan model. PMID:19226969

Imran, Mohammad; Yar, Mohammad Shahar; Khan, Suroor Ahmad

2009-01-01

49

Management of 3-aminopyridine-2-carboxaldehyde thiosemicarbazone-induced methemoglobinemia  

PubMed Central

The anticancer agent 3-aminopyridine-2-carboxaldehyde thiosemicarbazone is a ribonucleotide reductase inhibitor. It inactivates ribonucleotide reductase by disrupting an iron-stabilized radical in ribonucleotide reductase's small subunits, M2 and M2b (p53R2). Unfortunately, 3-aminopyridine-2-carboxaldehyde thiosemicarbazone also alters iron II (Fe2+) in hemoglobin. This creates Fe3+ methemoglobin that does not deliver oxygen. Fe2+ in hemoglobin normally auto-oxidizes to inactive Fe3+ methemoglobin at a rate of nearly 3% per day and this is counterbalanced by a reductase system that normally limits methemoglobin concentrations to less than 1% of hemoglobin. This balance may be perturbed by symptomatic toxicity levels during 3-aminopyridine-2-carboxaldehyde thiosemicarbazone therapy. Indications of 3-aminopyridine-2-carboxaldehyde thiosemicarbazone sequelae attributable to methemoglobinemia include resting dyspnea, headaches and altered cognition. Management of methemoglobinemia includes supplemental oxygen, ascorbate and, most importantly, intravenously administered methylene blue as a therapeutic antidote.

Kunos, Charles A; Radivoyevitch, Tomas; Ingalls, Stephen T; Hoppel, Charles L

2012-01-01

50

Potential antitumor agents. 12. 2-Formyl-4-aminophenylpyridine thiosemicarbazones.  

PubMed

The antitumor agent 2-formyl-4-(m-amino)phenylpyridine thiosemicarbazone (4-APPT) has been synthesized by a new route to give significantly better overall yields than previously reported. 4-Phenyl-2-picoline was formed by methylation o4-phenylpyridine with CH3Li which upon nitration produced a mixture of o-, m-, and p-nitro-substituted derivatives. These isomers were separated by the solubility differences of their hydrochloride or nitrate salts in 10, 27, and 40% yields, respectively. Identification and confirmation of the structure of these isomers were carried out by mmr. Each isomer was individually subjected to a series of reactions to oxidize the 2-CH3 group to the corresponding carboxaldehyde and to reduce the NO2 function to an amino group. These agents were tested for antineoplastic activity in mice bearing Sarcoma 180 ascites cells; while the o- and p-amino-substituted derivatives were inactive, the m-amino-substituted agent (4-APPT) approved to be an extremely potent antineoplastic agent. PMID:1121002

Agrawal, K C; Booth, B A; DeNuzzo, S M; Sartorelli, A C

1975-04-01

51

Antitumor activity of (-)-alpha-bisabolol-based thiosemicarbazones against human tumor cell lines.  

PubMed

A series of thiosemicarbazones deriving from the natural sesquiterpene (-)-alpha-bisabolol were synthesized and tested against a panel of eight human tumor cell lines to evaluate their anti-tumor potential. Some of the compounds exhibited inhibitory effects on the growth of a wide range of cancer cell lines, but myeloid leukemia cells (K-562) were especially sensitive to all tested thiosemicarbazones (GI(50) 0.01-4.22 microM). Among the analogues, the ketone derivative 3l was the most active, exhibiting potent antitumoral activity (GI(50) 0.01 microM) and high selectivity for K-562 cells (deltaTGI 505). It also demonstrated high cytotoxicity, with an LC(50) of 1.55 microM for the K-562 cells, but it showed only moderate selectivity (deltaLC(50) 38.5 microM). Through structure-activity relationship studies, we identified some structural requirement for the antitumoral activity exhibited by these promising compounds. PMID:20413188

da Silva, Alan P; Martini, Manuele V; de Oliveira, Cecília M A; Cunha, Silvio; de Carvalho, João E; Ruiz, Ana L T G; da Silva, Cleuza C

2010-07-01

52

Kinetic studies on the oxidation of oxyhemoglobin by biologically active iron thiosemicarbazone complexes: relevance to iron-chelator-induced methemoglobinemia.  

PubMed

The oxidation of oxyhemoglobin to methemoglobin has been found to be facilitated by low molecular weight iron(III) thiosemicarbazone complexes. This deleterious reaction, which produces hemoglobin protein units unable to bind dioxygen and occurs during the administration of iron chelators such as the well-known 3-aminopyridine-2-pyridinecarbaldehyde thiosemicarbazone (3-AP; Triapine), has been observed in the reaction with Fe(III) complexes of some members of the 3-AP structurally-related thiosemicarbazone ligands derived from di-2-pyridyl ketone (HDpxxT series). We have studied the kinetics of this oxidation reaction in vitro using human hemoglobin and found that the reaction proceeds with two distinct time-resolved steps. These have been associated with sequential oxidation of the two different oxyheme cofactors in the ? and ? protein chains. Unexpected steric and hydrogen-bonding effects on the Fe(III) complexes appear to be the responsible for the observed differences in the reaction rate across the series of HDpxxT ligand complexes used in this study. PMID:24317633

Basha, Maram T; Rodríguez, Carlos; Richardson, Des R; Martínez, Manuel; Bernhardt, Paul V

2014-03-01

53

QSAR Studies of Copper Azamacrocycles and Thiosemicarbazones  

PubMed Central

Genetic algorithms (GA) were used to develop specific copper metal-ligand force field parameters for the MM3 force field, from a combination of crystallographic structures and ab initio calculations. These new parameters produced results in good agreement with experiment and previously reported copper metal-ligand parameters for the AMBER force field. The MM3 parameters were then used to develop several Quantitative Structure Activity Relationship (QSAR) models. A successful QSAR for predicting the lipophilicity (logPow) of several classes of Cu(II) chelating ligands, was built using a training set of thirty-two Cu(II) radiometal complexes and six simple molecular descriptors. The QSAR exhibited a correlation between the predicted and experimental logPow with a r2 = 0.95, q2 = 0.92. When applied to an external test set of eleven Cu(II) complexes the QSAR preformed with great accuracy; r2 = 0.93 and a q2 = 0.91 utilizing a leave-one-out cross-validation analysis. Additional QSAR models were developed to predict the biodistribution of a smaller set of Cu(II) bis(thiosemicarbazone) complexes.

Wolohan, Peter; Yoo, Jeongsoo; Welch, Michael J.; Reichert, David E.

2008-01-01

54

Vacuum ultraviolet spectra of styrene, benzaldehyde, acetophenone, and benzonitrile  

Microsoft Academic Search

The vacuum ultraviolet absorption spectra of styrene, benzaldehyde, acetophenone and benzonitrile have been measured in the wavelength region of 1500 to 2200 Å. The absorption bands in the vacuum ultraviolet region appear at 200, 196, 189, 180 and 163 mµ for styrene; at 195,186, 178 and 165 mµ for benzaldehyde; at 196, 191, 179 and 167 mµ for acetophenone; at

Katsumi Kimura; Saburo Nagakura

1965-01-01

55

Synthesis and evaluation of copper radiopharmaceuticals with mixed bis(thiosemicarbazone) ligands.  

PubMed

Four "mixed" bis(thiosemicarbazone) derivatives of pyruvaldehyde were synthesized that incorporate two dissimilar thiosemicarbazone functions. The corresponding [67Cu]copper(II) complexes were prepared and evaluated as possible copper radiopharmaceuticals. The pyruvaldehyde-based mixed bis(thiosemicarbazone) ligands, CH3C[=NNHC(S)NHMe]CH[=NNHC(S)NHEt] (1), CH3C[=NNHC(S)NHMe] CH[=NNHC(S)NEt2] (2), CH3C[=NNHC(S)NHMe]CH[=NNHC(S)-cyclo-N(CH2)5] (3), and CH3C [=NNHC(S)NHMe]CH[=NNHC(S)-cyclo-N(CH2)6] (4), were obtained by reaction of the appropriate thiosemicarbazide derivative with pyruvaldehyde-2-N4-methylthiosemicarbazone (CH3C[=NNHC(S) NHMe]CHO). The 67Cu-labeled copper(II) complexes of ligands 1-4 were prepared and screened in a rat model to assess the potential of each chelate as a 62Cu-radiopharmaceutical for imaging with positron emission tomography. The 67Cu-complexes of ligands 1-4 exhibit significant uptake into the brain and heart 1 min following intravenous administration to rats. For the 67Cu-complexes of ligands 2, 3, and 4, the cerebral and myocardial uptake of 67Cu is two-to-threefold lower at 2 h than at 1 min postinjection, due to significant biological clearance of these 67Cu-chelates. However, the 67Cu-complex of 1 affords cerebral and myocardial uptake and retention comparable to that of [67Cu]Cu-PTSM in this model. Although the kinetics of this new agent appear attractive, ultrafiltration studies using solutions of dog and human serum albumin reveal that the 67Cu-complex of ligand 1, like Cu-PTSM, interacts more strongly with human albumin than dog albumin. Thus, this new agent would appear to offer no advantage over Cu-PTSM as a 62Cu-labeled tracer for evaluation of regional tissue perfusion. PMID:10473194

Ackerman, L J; West, D X; Mathias, C J; Green, M A

1999-07-01

56

Synthesis and Biochemical Evaluation of Thiochromanone Thiosemicarbazone Analogues as Inhibitors of Cathepsin L  

PubMed Central

A series of 36 thiosemicarbazone analogues containing the thiochromanone molecular scaffold functionalized primarily at the C-6 position were prepared by chemical synthesis and evaluated as inhibitors of cathepsins L and B. The most promising inhibitors from this group are selective for cathepsin L and demonstrate IC50 values in the low nanomolar range. In nearly all cases, the thiochromanone sulfide analogues show superior inhibition of cathepsin L as compared to their corresponding thiochromanone sulfone derivatives. Without exception, the compounds evaluated were inactive (IC50 > 10000 nM) against cathepsin B. The most potent inhibitor (IC50 = 46 nM) of cathepsin L proved to be the 6,7-difluoro analogue 4. This small library of compounds significantly expands the structure–activity relationship known for small molecule, nonpeptidic inhibitors of cathepsin L.

2012-01-01

57

2-Hydroxy-imino-1-phenyl-ethanone thio-semicarbazone monohydrate  

PubMed Central

In the title thio­semicarbazone derivative, C9H10N4OS·H2O, intra­molecular N—H?N hydrogen bonds result in the formation of two nearly coplanar five- and six-membered rings, which are also almost coplanar with the adjacent phenyl ring. The oxime group has an E configuration and is involved in inter­molecular O—H?O hydrogen bonding as a donor. In the crystal structure, intra­molecular O—H?S and N—H?N and inter­molecular O—H?O and N—H?S hydrogen bonds generate edge-fused R 2 2(8) and R 4 1(11) ring motifs. The hydrogen-bonded motifs are linked to each other to form a three-dimensional supra­molecular network.

Sar?kavakl?, Nursabah; Babahan, Iknur; Sahin, Ertan; Hokelek, Tuncer

2008-01-01

58

Efficient synthesis of functionalized dihydroquinolines, quinolines and dihydrobenzo[b]azepine via an iron(III) chloride-catalyzed intramolecular alkyne-carbonyl metathesis of alkyne tethered 2-amino benzaldehyde/acetophenone derivatives.  

PubMed

In this study we have developed an efficient synthesis of 1,2-dihydroquinoline and dihydrobenzo[b]azepine derivatives involving the iron(III) chloride intramolecular alkyne-carbonyl metathesis reaction for the first time. Various functionalized 1,2-dihydroquinolines and dihydrobenzo[b]azepines were prepared from easily accessible substrates in the presence of environmentally friendly and inexpensive iron(III) chloride (10 mol%) under mild conditions. The method is applicable to a wide range of substrates containing different functional groups and furnishing products in good to excellent yields. This methodology was further extended to the one-pot synthesis of 3-acyl quinolines via alkyne-carbonyl metathesis/detosylation/aromatization of N-propargyl-2-aminobenzaldehyde/acetophenone derivatives by the addition of NaOH/EtOH. While many Lewis acid and Brønsted acid catalysts were investigated, anhydrous iron(III) chloride turned out to be the best catalyst for this transformation. PMID:24500306

Jalal, Swapnadeep; Bera, Krishnendu; Sarkar, Soumen; Paul, Kartick; Jana, Umasish

2014-03-21

59

Structural and spectral studies of copper(II) and nickel(II) complexes of pyruvaldehyde mixed bis{N(4)-substituted thiosemicarbazones}  

Microsoft Academic Search

Pyruvaldehyde mixed bis(thiosemicarbazones) have been prepared in which the two thiosemicarbazone moieties have different N(4)-substituents. The mixed bis(thiosemicarbazones) and their copper(II) and nickel(II) complexes have been characterized with IR, electronic, mass, 1H NMR (Ni) and EPR (Cu) spectra. Representative crystal structures have been solved of nickel(II) complexes with either a pyruvaldehyde mixed bis(thiosemicarbazone) or a bis(thiosemicarbazone) with identical N(4)-substituents acting

Lily J. Ackerman; Phillip E. Fanwick; Mark A. Green; Elizabeth John; William E. Running; John K. Swearingen; James W. Webb; Douglas X. West

1999-01-01

60

Versatile coordinative abilities of a new hybrid pteridine-thiosemicarbazone ligand: crystal structure, spectroscopic characterization, and luminescent properties.  

PubMed

The synthesis and characterization of the first thiosemicarbazone-lumazine (TSCLMH=the thiosemicarbazone of 6-acetyl-1,3,7-trimethyllumazine) hybrid ligand is reported. The influence of the conformation of this compound on its energy and the atomic contribution to the molecular orbitals have been theoretically investigated. Ni(II), Cu(I), Zn(II), and Cd(II) complexes of this ligand have been synthesized and characterized by elemental analysis, thermogravimetric studies, IR, 1H, 13C, and 15N NMR, and UV-vis-NIR spectroscopy, magnetic measurements, and X-ray crystallography. Four types of coordination modes for the ligand may be predicted: (a) double bidentate; (b) tetradentate; (c) tridentate; (d) bidentate. Structures of representative complexes of types a, b, and d have been determined by X-ray crystallography. In the [Cu(TSCLMH)]2(ClO4)2 complex, TSCLMH acts as a doubly bidentate bridging ligand forming a dimer with a Cu...Cu distance of 2.876 A. The geometry around the metal ion is trigonally distorted tetrahedral with a relatively long (four-atom) bridge between the metal centers instead of the shorter, mainly single atom, bridges present in other thiosemicarbazone derivatives complexes. In the [Cd(NO3)2(TSCLMH)(EtOH)] complex, the metal ion displays eight-coordinated geometry with the TSCLMH ligand acting in a tetradentate planar fashion and two nitrate anions, one monodentate and the other bidentate. The coordination polyhedron in [Cd(TSCLM)2(H2O)].MeOH.2H2O is a square pyramid with two monoanionic ligands acting as bidentate NS donors and a water molecule completing the coordination sphere. Fluorescence spectroscopic properties of TSCLMH have been studied as well as the changes in position and intensity of fluorescence bands caused by the complexation with different metal ions (Ni2+, Cu+, Zn2+, Cd2+). PMID:18186630

Jiménez-Pulido, Sonia B; Linares-Ordóñez, Fátima M; Moreno-Carretero, Miguel N; Quirós-Olozábal, Miguel

2008-02-01

61

Synthesis and characterization of mixed-ligand diimine-piperonal thiosemicarbazone complexes of ruthenium(II): Biophysical investigations and biological evaluation as anticancer and antibacterial agents  

NASA Astrophysics Data System (ADS)

We have used a novel microwave-assisted method developed in our laboratories to synthesize a series of ruthenium-thiosemicarbazone complexes. The new thiosemicarbazone ligands are derived from benzo[ d][1,3]dioxole-5-carbaldehyde (piperonal) and the complexes are formulated as [(diimine) 2Ru(TSC)](PF 6) 2 (where the TSC is the bidentate thiosemicarbazone ligand). The diimine in the complexes is either 2,2'-bipyridine or 1,10-phenanthroline. The complexes have been characterized by spectroscopic means (NMR, IR and UV-Vis) as well as by elemental analysis. We have studied the biophysical characteristics of the complexes by investigating their anti-oxidant ability as well as their ability to disrupt the function of the human topoisomerase II enzyme. The complexes are moderately strong binders of DNA with binding constants of 10 4 M -1. They are also strong binders of human serum albumin having binding constants on the order of 10 4 M -1. The complexes show good in vitro anticancer activity against human colon cancer cells, Caco-2 and HCT-116 and indeed show some cytotoxic selectivity for cancer cells. The IC 50 values range from 7 to 159 ?M (after 72 h drug incubation). They also have antibacterial activity against Gram-positive strains of pathogenic bacteria with IC 50 values as low as 10 ?M; little activity was seen against Gram-negative strains. It has been established that all the compounds are catalytic inhibitors of human topoisomerase II.

Beckford, Floyd A.; Thessing, Jeffrey; Shaloski, Michael, Jr.; Canisius Mbarushimana, P.; Brock, Alyssa; Didion, Jacob; Woods, Jason; Gonzalez-Sarrías, Antonio; Seeram, Navindra P.

2011-04-01

62

Adsorption, mobility, and dimerization of benzaldehyde on Pt(111)  

NASA Astrophysics Data System (ADS)

Building on results for the adsorption of benzene on Pt(111), the adsorption of benzaldehyde is investigated using density functional theory. Benzaldehyde is found to chemisorb preferentially with its aromatic ring in the flat-lying bridge geometry that is also preferred for benzene. Across the investigated geometries, adsorption is homogeneously weakened compared to corresponding benzene geometries. This is found to be true for very different adsorption modes, namely, ?6 and ?8 modes, the latter having metal atoms inserted in the carbonyl bond. Reorientation and diffusion of benzaldehyde is found to have low energy barriers. Aggregation of molecules in dimers bound by aryl C-H...O hydrogen bonds is investigated, and specific configurations are found to be up to 0.15 eV more favorable than optimally configured, separated adsorbates. The binding is significantly stronger than what is found for gas phase dimers, suggesting an enhancing effect of the metal interaction.

Rasmussen, Anton M. H.; Hammer, Bjørk

2012-05-01

63

Synthesis, characterization and biological evaluation of paeonol thiosemicarbazone analogues as mushroom tyrosinase inhibitors.  

PubMed

A series of hydroxy- and methoxy-substituted paeonol thiosemicarbazone analogues were synthesized as potential tyrosinase inhibitors and their inhibitory effects on mushroom tyrosinase and inhibitory mechanism were evaluated. Paeonol thiosemicarbazone analogues have been found exhibiting more remarkable inhibition than their indexcompounds on mushroom tyrosinase. Among them, compound 2,4-dihydroxy acetophenone-4-phenyl-3-thiosemicarbazone (d1) had the most potent inhibition activity with the IC50 value of 0.006 ± 0.001 mM, displayed as a reversible competitive inhibitor. The inhibitory ability of o- or p-substituted acetophenone thiosemicarbazones was: di-substituted acetophenone thiosemicarbazones>mono-substituted acetophenone thiosemicarbazones>non-substituted acetophenone thiosemicarbazones. Copper ions chelation assay explained that compound d1 exhibited competitive inhibition by forming a chelate with the copper ions at the catalytic domain of tyrosinase as well as indicate a 1.5:1 binding ratio of compound d1 with copper ions. In the fluorescence spectrum study, compound d1 behaved stronger fluorescence quenching on tyrosinase towards d1-Cu(2+) complex, inhibiting tyrosinase mainly by means of chelating the two copper ions in the active site. The newly synthesized compounds may serve as structural templates for designing and developing novel tyrosinase inhibitors. PMID:24120880

Zhu, Tian-Hua; Cao, Shu-Wen; Yu, Yan-Ying

2013-11-01

64

Benzaldehyde conversion by two anaerobic bacteria isolated from an upflow anaerobic sludge bed reactor  

Microsoft Academic Search

A benzaldehyde-degrading enrichment culture was obtained from mesophilic methanogenic granular sludge from a UASB (upflow anaerobic sludge bed) reactor treating potato starch wastewater. The enrichment culture degraded benzaldehyde rapidly to benzylalcohol and benzoate. Two benzaldehyde-degrading bacterial strains were isolated from the enrichment. Both strains could grow on yeast extract in the presence or absence of benzaldehyde. Strain BOR (DSM 12?858)

S. N. Parshina; R. Kleerebezem; E van Kempen; A. N. Nozhevnikova; G. Lettinga; A. J. M. Stams

2000-01-01

65

Desymmetrisation of C 2-symmetric (2 S,3 S)-diazidobutane-1,4-diol with benzaldehyde  

Microsoft Academic Search

Surprisingly, doubly functionalised (2S,3S)-diazidobutane-1,4-diol under modified Boyer conditions reacted with only 1equiv of benzaldehyde yielding a mono oxazoline, whereas quantum chemical studies favour the formation of the C2-symmetric bioxazoline. In addition, the oxazoline formation was indirectly confirmed via detailed NMR studies and X-ray structure analysis of the oxazoline p-nitrobenzoic acid ester derivative.

Andreas Scheurer; Walter Bauer; Frank Hampel; Christine Schmidt; Rolf W. Saalfrank; Paul Mosset; Ralph Puchta; Nico J. R. van Eikema Hommes

2004-01-01

66

Direct olefination of benzaldehydes into 1,3-diarylpropenes via a copper-catalyzed heterodomino Knoevenagel-decarboxylation-Csp(3)-H activation sequence.  

PubMed

Copper-catalyzed direct olefination of benzaldehydes into 1,3-diarylpropenes by a novel domino Knoevenagel-decarboxylation-Csp(3)-H activation sequence is reported. This method provides a concise and effective route toward the synthesis of unsymmetrical 1,3-diarylpropene derivatives. PMID:24752597

Zhao, Yaping; Sun, Lu; Zeng, Tieqiang; Wang, Jiayi; Peng, Yanqing; Song, Gonghua

2014-06-01

67

A spectral study of 2-formylimidazole 4N-substituted thiosemicarbazones and their copper(II) complexes  

NASA Astrophysics Data System (ADS)

Copper(II) complexes of 2-formylimidazole 4N-methyl-, 4N-dimethyl- 4N-ethyl- and 3-hexa-methyleneiminylthiosemicarbazone, along with two nickel(II) complexes of the latter thiosemicarbazone, have been synthesized. Infrared, electronic, NMR and ESR spectra have been used to characterize the complexes and the uncomplexed thiosemicarbazones. None of the complexes or thiosemicarbazones possess growth inhibitory activity against Aspergillus niger and Paecilomyces variotii.

West, Douglas X.; Lockwood, Mark A.; Albert, Julyan N.; Liberta, Anthony E.

1993-11-01

68

Effect of molecular structure on the efficiency of amides and thiosemicarbazones used for corrosion inhibition of mild steel in hydrochloric acid 1 This paper is based on part of a contribution to the 31st Annual Conference of the Nigeria Mining and Geosciences Society (NMGS) held at Calabar, Nigeria, 12–16 March, 1995. 1  

Microsoft Academic Search

The effect of changing functional groups of some amides and thiosemicarbazone derivatives on their inhibition efficiency has been reported with a view to establishing a relationship between inhibitor efficiency and molecular structure, using the weight loss and hydrogen evolution techniques. The compounds used for this study are urea (U), thiourea (TU), acetamide (A), thioacetamide (TA), semicarbazide (SC), thiosemicarbazide (TSC), methoxybenzaldehyde

E. E. Ebenso; U. J. Ekpe; B. I. Ita; O. E. Offiong; U. J. Ibok

1999-01-01

69

Synthesis, spectroscopic characterization of thiosemicarbazone complexes of nickel(II) and X-ray structures of anisaldehyde thiosemicarbazone (ATSZH) and bis(tolualdehyde thiosemicarbazonato)nickel(II)  

Microsoft Academic Search

Complexes of nickel(II) with anisaldehyde (ATSZH), tolualdehyde (TTSZH), and vanillin (VTSZH) thiosemicarbazones have been synthesized and characterized by means of UV-Visible, I.R., Raman,1H and13C NMR spectroscopy. The thiosemicarbazones have been found to exist in the thione form.1H and13C NMR as well as electronic spectral data support a square planar structure for Ni(ATSZ)2 and Ni(TTSZ)2 complexes.1H and13C NMR spectra indicate that

N. T. Akinchan; R. Akinchan; U. J. Ibok; L. P. Battaglia; A. Bonamartini Corradi; P. Dro?d?ewski

1992-01-01

70

Condensation of benzaldehyde diethyl acetal with ethyl vinyl ether  

Microsoft Academic Search

Summary 1.A study was made of the condensation of benzaldehyde diethyl acetal with ethyl vinyl ether.2.It was shown that in this reaction aliphatic-aromatic ethoxy acetals of general formula C6H5 -(CHOC2H5-CH2)nCH(OC2H5)2 are formed.3.By the hydrolysis of these ethoxy acetals, aliphatic-aromatic ethoxy aldehydes were prepared.

B. M. Mikhailov; L. S. Povarov

1957-01-01

71

Carboligation reactions with benzaldehyde lyase immobilized on superparamagnetic solid support.  

PubMed

Histidine-tagged recombinant benzaldehyde lyase (BAL, EC 4.1.2.38) was efficiently immobilized to surface-modified magnetic particles with affinity ligand binding. In addition to conventional benzoin condensation reactions, two important representative BAL-catalyzed carboligation reactions, were also performed with this magnetically responsive biocatalyst. The results obtained from the carboligation reactions that were performed with this simple and convenient heterogenous biocatalyst were comparable to that of free-enzyme-catalyzed reactions. PMID:19343254

Sopaci, S Betül; Sim?ek, Ilke; Tural, Bilsen; Volkan, Mürvet; Demir, Ayhan S

2009-04-21

72

Biomass pyrolysis: thermal decomposition mechanisms of furfural and benzaldehyde.  

PubMed

The thermal decompositions of furfural and benzaldehyde have been studied in a heated microtubular flow reactor. The pyrolysis experiments were carried out by passing a dilute mixture of the aromatic aldehydes (roughly 0.1%-1%) entrained in a stream of buffer gas (either He or Ar) through a pulsed, heated SiC reactor that is 2-3 cm long and 1 mm in diameter. Typical pressures in the reactor are 75-150 Torr with the SiC tube wall temperature in the range of 1200-1800 K. Characteristic residence times in the reactor are 100-200 ?sec after which the gas mixture emerges as a skimmed molecular beam at a pressure of approximately 10 ?Torr. Products were detected using matrix infrared absorption spectroscopy, 118.2 nm (10.487 eV) photoionization mass spectroscopy and resonance enhanced multiphoton ionization. The initial steps in the thermal decomposition of furfural and benzaldehyde have been identified. Furfural undergoes unimolecular decomposition to furan + CO: C4H3O-CHO (+ M) ? CO + C4H4O. Sequential decomposition of furan leads to the production of HC?CH, CH2CO, CH3C?CH, CO, HCCCH2, and H atoms. In contrast, benzaldehyde resists decomposition until higher temperatures when it fragments to phenyl radical plus H atoms and CO: C6H5CHO (+ M) ? C6H5CO + H ? C6H5 + CO + H. The H atoms trigger a chain reaction by attacking C6H5CHO: H + C6H5CHO ? [C6H6CHO]* ? C6H6 + CO + H. The net result is the decomposition of benzaldehyde to produce benzene and CO. PMID:24050347

Vasiliou, AnGayle K; Kim, Jong Hyun; Ormond, Thomas K; Piech, Krzysztof M; Urness, Kimberly N; Scheer, Adam M; Robichaud, David J; Mukarakate, Calvin; Nimlos, Mark R; Daily, John W; Guan, Qi; Carstensen, Hans-Heinrich; Ellison, G Barney

2013-09-14

73

Half-sandwich ruthenium-arene complexes with thiosemicarbazones: Synthesis and biological evaluation of [(?6-p-cymene)Ru(piperonal thiosemicarbazones)Cl]Cl complexes  

PubMed Central

The synthesis and characterization of a number of organometallic ruthenium(II) complexes containing a series of bidentate thiosemicarbazone ligands derived from piperonal is reported. The structure of compounds have been confirmed by spectroscopic analysis (IR and NMR) as well as X-ray crystallographic analysis of [(?6-p-cymene)Ru(pPhTSC)Cl]Cl (4) (pPhTSC is piperonal-N(4)-phenylthiosemicarbazone). The interaction of the complexes ([(?6-p-cymene)Ru(pEtTSC)Cl]Cl) (3) (pEtTSC is piperonal-N(4)-ethylthiosemicarbazone) and 4 with calf thymus DNA, human serum albumin (HSA) and pBR322 plasmid DNA were studied by spectroscopic, gel electrophoresis and hydrodynamic methods. The apparent binding constant for the interaction with DNA was determined to be 3.97 × 103 M?1 and 4.07 × 103 M?1 at 293 K for 3 and 4 respectively. The complexes bind strongly to HSA with binding constants of 2.94 × 104 M?1 and 12.2 × 104 M?1 at 296 K for 3 and 4 respectively. The in vitro anticancer activity of 3 and 4 has been evaluated against two human colon cancer cell line (HCT-116 and Caco-2) with IC50 values in the range 26 – 150 µM. Both 3 and 4 show good activity as a catalytic inhibitor of human topoisomerase II at concentrations as low as 20 µM. The proficiency of 3 and 4 to act as antibacterial agents was also evaluated against six pathogenic bacterial strains with the best activity seen against Gram-positive strains.

Dourth, Deidra; Shaloski, Michael; Didion, Jacob; Thessing, Jeffrey; Woods, Jason; Crowell, Vernon; Gerasimchuk, Nikolay; Gonzalez-Sarrias, Antonio; Seeram, Navindra P.

2011-01-01

74

Synthesis, characterization, and in vitro anti-neoplastic activity of novel vic-dioximes bearing thiosemicarbazone side groups and their mononuclear complexes.  

PubMed

Two novel vicinal dioxime ligands containing thiosemicarbazone units, (2E)-2-[4-(diethylamino)benzylidene]-N-[(1Z,2E)-N-hydroxy-2-(hydroxyimino)ethanimidoyl]hydrazine carbothioamide (L(1)H2) and (2E)-2-[4-(dimethylamino)benzylidene]-N-[(1Z,2E)-N-hydroxy-2-(hydroxyimino)ethanimidoyl]hydrazinecarbothioamide (L(2)H2), were synthesized. Using the HL-60 human leukemia cell line, the in vitro anti-neoplastic activity of these thiosemicarbazone-oxime derivatives was evaluated. Mononuclear nickel(II), copper(II), and cobalt(II) complexes with a metal:ligand ratio of 1:2 for both the L(1)H2 and L(2)H2 ligands were also synthesized. To characterize these compounds, Fourier transform-infrared spectroscopy (FT-IR), mass spectrometry (MS), magnetic susceptibility measurements, (1)H and (13)C nuclear magnetic resonance (NMR), ultraviolet-visible (UV-Vis) absorption spectroscopy, heteronuclear multiple-bond correlation (HMQC), and elemental analysis were performed. For L(1)H2, L(2)H2, and each of their derivatives, antiproliferative effects against HL-60 cells were exhibited and the associated IpC50 values ranged from 5?M to 20?M. Furthermore, L(1)H2 and its derivatives inhibited the proliferation of HL-60 cells more effectively than L(2)H2, and 5?M [Cu(L(1)H)2] exhibited the strongest antiproliferative activity. PMID:24651042

Babahan, ?lknur; Özmen, Ali; Orhan, Nil; Kazar, Didem; De?irmenci, Esin Hafize

2014-04-01

75

Design, synthesis and biological evaluation of new aryl thiosemicarbazone as antichagasic candidates.  

PubMed

The present work reports on the synthesis, biological assaying and docking studies of a series of 12 aryl thiosemicarbazones, which were planned to act over two main enzymes, cruzain and trypanothione reductase. These enzymes are used as targets of trypanocidal activity in Chagas disease control with a minimal mutagenic profile. Three p-nitroaromatic thiosemicarbazones showed high activity against Trypanosoma cruzi in in vitro assays (IC50 < 57 ?M), and no mutagenic profile was observed in micronucleous tests. Although the in vitro inhibition test showed that 10-?M doses of eight compounds inhibited cruzain activity, no correlation was found between cruzain inhibition and trypanocidal activity. PMID:23851115

Blau, Lorena; Menegon, Renato Farina; Trossini, Gustavo H G; Molino, João Vitor Dutra; Vital, Drielli Gomes; Cicarelli, Regina Maria Barretto; Passerini, Gabriela Duó; Bosquesi, Priscila Longhin; Chin, Chung Man

2013-09-01

76

Magnetic and Spectroscopic Studies of Cr(III) Complexes of Semicarbazones and Thiosemicarbazones  

Microsoft Academic Search

Cr(III) complexes of the type [crCl2 (NX).2H2O] and [CrCl(NX)2.H2O] have been synthesised by the reaction of Cr (III) chloride with biologically active Schiff bases, viz. furfur-aldehyde semicarbazone I (X=O), furfuraldehyde thiosemicarbazone (I) (X=S), indole-3-carboxaldehyde semicarbazone II (X=O) and indole-3-carboxaldehyde thiosemicarbazone (II) (X=S). These complexes have been characterized on the basis of elemental analyses and physicochemical measurements. The complexes behave as

Archana Garg; J. P. Tandon

1990-01-01

77

Synthesis and Coordinating Properties of New Chromone Thiosemicarbazones Towards Some Transition Metal Ions  

Microsoft Academic Search

Copper(II), iron(III), cobalt(II,III), nickel(II), chromium(III), palladium(II), platinum(IV) and zinc(II) complexes of 2?methyl?7?hydroxy?5?methoxy?6?formyl chromone thiosemicarbazone (H2L), 2?methyl?5,7?dimethoxy?6?formyl chromone thiosemicarbazone (HL) have been prepared and characterized by conductance, magnetic, electronic, infrared and H NMR spectroscopic measurements as well as elemental and thermogravimetrical analyses. Octahedral structures are proposed for the Pt(IV), Fe(III), Co(II), Co(III), and Cr(III) complexes, whereas square–planar configurations are suggested for

Nabil S. Youssef; K. H. Hegab; A. E. Eid

2003-01-01

78

Rhenium mixed-ligand complexes with S,N,S-tridentate thiosemicarbazone/thiosemicarbazide ligands.  

PubMed

Rhenium(V) complexes containing tridentate thiosemicarbazones/thiosemicarbazides (H2L1) derived from N-[N?,N?-dialkylamino(thiocarbonyl)]benzimidoyl chlorides with 4,4-dialkylthiosemicarbazides have been synthesized by ligand-exchange reactions starting from [ReOCl(L1)]. The chlorido ligand of [ReOCl(L1)] (4) is readily replaced and reactions with ammonium thiocyanate or potassium cyanide give [ReO(NCS)(L1)] (6) and [ReO(CN)(L1)] (7), respectively. The reaction of (NBu4)[ReOCl4] with H2L1 and two equivalents of ammonium thiocyanate, however, gives in a one-pot reaction [ReO(NCS)2(HL1)] (8), in which the pro-ligand H2L1 is only singly deprotonated. An oxo-bridged, dimeric nitridorhenium(V) compound of the composition [{ReN(HL1)}2O] (11) is obtained from a reaction of (NBu4)[ReOCl4], H2L1 and sodium azide. The six-coordinate complexes [ReO(L1)(Ph2btu)] (12), where HPh2btu is N,N-diphenyl-N?-benzoylthiourea, can be obtained by treatment of [ReOCl(L1)] with HPh2btu in the presence of NEt3. Studies of the antiproliferative effects of the [ReOX(L1)] system (X = Cl?, NCS? or CN?) on breast cancer cells show that the lability of a monodentate ligand seems to play a key role in the cytotoxic activity of the metal complexes, while the substitution of this ligand by the chelating ligand Ph2btu? completely terminates the cytotoxicity. PMID:23400226

Maia, Pedro I da S; Nguyen, Hung Huy; Hagenbach, Adelheid; Bergemann, Silke; Gust, Ronald; Deflon, Victor M; Abram, Ulrich

2013-04-14

79

Influence of Photosensitive Group Concentration on Birefringence Induced in Benzaldehyde Polymers  

NASA Astrophysics Data System (ADS)

Induction of optical anisotropy in benzaldehyde polymer layers by linearly polarized UV radiation was investigated experimentally. Negative dichroism in absorption spectra and strong negative birefringence (-2 · 10-3) were related to the presence of an oriented ensemble of residual benzaldehyde groups. The thermal stability of photoinduced birefringence at high photosensitive group concentration was associated with a high density of photocross-links formed between macromolecules.

Mahilny, U. V.; Stankevich, A. I.; Trofimova, A. V.

2014-01-01

80

Serotonin mediates a learned increase in attraction to high concentrations of benzaldehyde in aged C. elegans.  

PubMed

We utilized olfactory-mediated chemotaxis in Caenorhabditis elegans to examine the effect of aging on information processing and animal behavior. Wild-type (N2) young adults (day 4) initially approach and eventually avoid a point source of benzaldehyde. Aged adult animals (day 7) showed a stronger initial approach and a delayed avoidance to benzaldehyde compared with young adults. This delayed avoidance is due to an increased attraction rather than a decreased avoidance to benzaldehyde because (1) aged odr-3 mutants that are defective in odor attraction showed no delayed benzaldehyde avoidance, and (2) the delay in avoidance was also observed with another attractant diacetyl, but not the repellent octanol. Interestingly, the stronger expression of attractive behavior was only observed at benzaldehyde concentrations of 1% or higher. When worms were grown on nonbacterial growth media instead of Escherichia coli, thus removing the contingency between odors released from the food and the food itself, the increase in attraction to benzaldehyde disappeared. The increased attraction recovered after reinitiating the odor-food contingency by returning animals to E. coli food or supplementing axenic media with benzaldehyde. Moreover, serotonin-deficient mutants showed a deficit in the age-enhanced attraction. These results suggest that the increased attraction to benzaldehyde in aged worms is (1) serotonin mediated, (2) specific to high concentration of odorants, and (3) dependent on a learned association of odor metabolites with the presence of food. We propose that associative learning may selectively modify pathways at or downstream from a low-affinity olfactory receptor. PMID:18984566

Tsui, David; van der Kooy, Derek

2008-11-01

81

Surface Plasmon Resonance Based Sensitive Immunosensor for Benzaldehyde Detection  

NASA Astrophysics Data System (ADS)

Fragrant compounds used to add flavor to beverages remain in the manufacturing line after the beverage manufacturing process. Line cleanliness before the next manufacturing cycle is difficult to estimate by sensory analysis, making excessive washing necessary. A new measurement system to determine line cleanliness is desired. In this study, we attempted to detect benzaldehyde (Bz) using an anti-Bz monoclonal antibody (Bz-Ab) and a surface plasmon resonance (SPR) sensor. We fabricated two types of sensor chips using self-assembled monolayers (SAMs) and investigated which sensor surface exhibited higher sensitivity. In addition, anti-Bz antibody conjugated with horseradish peroxidase (HRP-Bz-Ab) was used to enhance the SPR signal. A detection limit of ca. 9ng/mL (ppb) was achieved using an immobilized 4-carboxybenzaldehyde sensor surface using SAMs containing ethylene glycol. When the HRP-Bz-Ab concentration was reduced to 30ng/mL, a detection limit of ca. 4ng/mL (ppb) was achieved for Bz.

Onodera, Takeshi; Shimizu, Takuzo; Miura, Norio; Matsumoto, Kiyoshi; Toko, Kiyoshi

82

Conversion of Phenylalanine to Benzaldehyde Initiated by an Aminotransferase in Lactobacillus plantarum  

PubMed Central

The production of benzaldehyde from phenylalanine has been studied in various microorganisms, and several metabolic pathways have been proposed in the literature for the formation of this aromatic flavor compound. In this study, we describe benzaldehyde formation from phenylalanine by using a cell extract of Lactobacillus plantarum. Phenylalanine was initially converted to phenylpyruvic acid by an aminotransferase in the cell extract, and the keto acid was further transformed to benzaldehyde. However, control experiments with boiled cell extract revealed that the subsequent conversion of phenylpyruvic acid was a chemical oxidation step. It was observed that several cations could replace the extract in the conversion of phenylpyruvic acid to benzaldehyde. Addition of Cu(II) ions to phenylpyruvic acid resulted not only in the formation of benzaldehyde, but also in the generation of phenylacetic acid, mandelic acid, and phenylglyoxylic acid. These compounds have been considered intermediates in the biological conversion of phenylalanine. The chemical conversion step of phenylpyruvic acid was dependent on temperature, pH, the availability of cations, and the presence of oxygen.

Nierop Groot, Masja N.; de Bont, Jan A. M.

1998-01-01

83

The benzaldehyde oxidation paradox explained by the interception of peroxy radical by benzyl alcohol.  

PubMed

Benzaldehyde readily undergoes autoxidation to form benzoic acid on exposure to air at room temperature. Yet it can be formed in high yield from, for example, benzyl alcohol by oxidation using a variety of procedures and catalysts. Here we report the evidence to resolve this apparent paradox. It is confirmed that benzyl alcohol (and a number of other alcohols), even at low concentrations in benzaldehyde, inhibits the autoxidation. Furthermore we report on the structural features required for inhibition. Electron paramagnetic resonance spin trapping experiments demonstrate that benzyl alcohol intercepts, by hydrogen atom transfer, the benzoylperoxy radicals that play a key role in benzaldehyde autoxidation. A similar inhibition effect has also been observed for the aliphatic octanal/1-octanol system. PMID:24567108

Sankar, Meenakshisundaram; Nowicka, Ewa; Carter, Emma; Murphy, Damien M; Knight, David W; Bethell, Donald; Hutchings, Graham J

2014-01-01

84

Antifungal activity of redox-active benzaldehydes that target cellular antioxidation  

PubMed Central

Background Disruption of cellular antioxidation systems should be an effective method for control of fungal pathogens. Such disruption can be achieved with redox-active compounds. Natural phenolic compounds can serve as potent redox cyclers that inhibit microbial growth through destabilization of cellular redox homeostasis and/or antioxidation systems. The aim of this study was to identify benzaldehydes that disrupt the fungal antioxidation system. These compounds could then function as chemosensitizing agents in concert with conventional drugs or fungicides to improve antifungal efficacy. Methods Benzaldehydes were tested as natural antifungal agents against strains of Aspergillus fumigatus, A. flavus, A. terreus and Penicillium expansum, fungi that are causative agents of human invasive aspergillosis and/or are mycotoxigenic. The yeast Saccharomyces cerevisiae was also used as a model system for identifying gene targets of benzaldehydes. The efficacy of screened compounds as effective chemosensitizers or as antifungal agents in formulations was tested with methods outlined by the Clinical Laboratory Standards Institute (CLSI). Results Several benzaldehydes are identified having potent antifungal activity. Structure-activity analysis reveals that antifungal activity increases by the presence of an ortho-hydroxyl group in the aromatic ring. Use of deletion mutants in the oxidative stress-response pathway of S. cerevisiae (sod1?, sod2?, glr1?) and two mitogen-activated protein kinase (MAPK) mutants of A. fumigatus (sakA?, mpkC?), indicates antifungal activity of the benzaldehydes is through disruption of cellular antioxidation. Certain benzaldehydes, in combination with phenylpyrroles, overcome tolerance of A. fumigatus MAPK mutants to this agent and/or increase sensitivity of fungal pathogens to mitochondrial respiration inhibitory agents. Synergistic chemosensitization greatly lowers minimum inhibitory (MIC) or fungicidal (MFC) concentrations. Effective inhibition of fungal growth can also be achieved using combinations of these benzaldehydes. Conclusions Natural benzaldehydes targeting cellular antioxidation components of fungi, such as superoxide dismutases, glutathione reductase, etc., effectively inhibit fungal growth. They possess antifungal or chemosensitizing capacity to enhance efficacy of conventional antifungal agents. Chemosensitization can reduce costs, abate resistance, and alleviate negative side effects associated with current antifungal treatments.

2011-01-01

85

Synthesis and spectroscopic study on photochromism of a new thiosemicarbazone compound containing pyrazolone  

NASA Astrophysics Data System (ADS)

A new photochromic compound 1,3-diphenyl-4-(4'-fluro)benzal-5-pyrazolone-4-ethyl thiosemicarbazone (DP4FBP-ETSC) was synthesized by direct condensation of 1,3-diphenyl-5-pyrazolone with N(4)-ethyl thiosemicarbazide. The product was characterized by elemental analysis, IR and 1H NMR spectra. The photochromic properties of the compound were studied using time-dependent fluorescence emission spectra, the UV-vis reflection spectra in the solid state and the UV-vis absorption spectroscopy in liquid. The reaction rate constant of compound was also analyzed. The results show that DP4FBP-ETSC can perform photochromism.

Chai, Hui; Liu, Guangfei; Liu, Lang; Jia, Dianzeng

2005-09-01

86

Synthesis, Spectral and Magnetic Investigation of 4-(2-pyridyl)-1salicylaldehyde3-thiosemicarbazone  

Microsoft Academic Search

Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), Pd(II) and dioxouranium(VI), (UO:2 ), complexes of 4-(2-pyridyl)-1-salicyldehyde-3-thiosemicarbazone (H2SBT) have been synthesized and characterised by elemental analyses, molar conductance, spectral (IR, visible and NMR) and magnetic moment measurement. IR spectral data show that the ligand behaves in a bi-, tri- and\\/or tetradentatc manner. An octahedral structure is proposed for Cr(HSBT)2Cl.H2O. Mn(HSBT)2,

Usama El-Ayaan; Gaber Abu El-Reash; Peter Weinberger; Wolfgang Linert

2000-01-01

87

Discovery of trypanocidal thiosemicarbazone inhibitors of rhodesain and TbcatB  

PubMed Central

Human African trypanosomiasis (HAT) is caused by the protozoan parasite Trypanosoma brucei. The cysteine proteases of T.brucei have been shown to be crucial for parasite replication and represent an attractive point for therapeutic intervention. Herein we describe the synthesis of a series of thiosemicarbazones and their activity against the trypanosomal cathepsins TbcatB and rhodesain, as well as human cathepsins L and B. The activity of these compounds was determined against cultured T.brucei, and specificity was assessed with a panel of four mammalian cell lines.

Mallari, Jeremy P.; Shelat, Anang; Kosinski, Aaron; Caffrey, Conor R.; Connelly, Michele; Zhu, Fangyi; McKerrow, James H.; Guy, R. Kiplin

2008-01-01

88

SYNTHESIS, CHARACTERIZATION, AND ELECTRICAL PROPERTIES OF METAL COMPLEXES OF 2-PYRIDINECARBALDEHYDE THIOSEMICARBAZONE  

Microsoft Academic Search

The synthesis, characterization, physico-chemical and electrical properties of complexes of pyridine-2-carbaldehyde thiosemicarbazone (PTSC) with transition element cations are reported. The complexes [Fe(PTSC)2Cl2]Cl and [Ni(PTSC)2-(H2O)2]Cl2 were prepared. Molecular structures of these complexes were identified by using elemental analyses, FT-IR, UV-VIS, thermogravimetric and molar conductivity techniques. The structure, along with other physico-chemical studies, established that the complexes of PTSC were low-spin. The

F. Yakuphanoglu; A. Balaban; F. Dagdelen; Y. Aydogdu; M. Sekerci; B. Erk

2002-01-01

89

Ligational behavior of thiosemicarbazone, semicarbazone and thiocarbohydrazone ligands towards VO(IV), Ce(III), Th(IV) and UO 2(VI) ions: Synthesis, structural characterization and biological studies  

NASA Astrophysics Data System (ADS)

Mono- and binuclear VO(IV), Ce(III), Th(IV) and UO 2(VI) complexes of thiosemicarbazone, semicarbazone and thiocarbohydrazone ligands derived from 4,6-diacetylresorcinol were synthesized. The structures of these complexes were elucidated by elemental analyses, IR, UV-vis, ESR, 1H NMR and mass spectra as well as conductivity and magnetic susceptibility measurements and thermal analyses. The thiosemicarbazone (H 4L 1) and the semicarbazone (H 4L 2) ligands behave as dibasic pentadentate ligands in case of VO(IV) and UO 2(VI) complexes, tribasic pentadentate in case of Ce(III) complexes and monobasic pentadentate in case of Th(IV) complexes. However, the thiocarbohydrazone ligand (H 3L 3) acts as a monobasic tridentate ligand in all complexes except the VO(IV) complex in which it acts as a dibasic tridentate ligand. The antibacterial and antifungal activities were also tested against Rhizobium bacteria and Fusarium-Oxysporium fungus. The metal complexes of H 4L 1 ligand showed a higher antibacterial effect than the free ligand while the other ligands (H 4L 2 and H 3L 3) showed a higher effect than their metal complexes. The antifungal effect of all metal complexes is lower than the free ligands.

Shebl, M.; Seleem, H. S.; El-Shetary, B. A.

2010-01-01

90

Conversion of benzaldehyde into benzyl benzoate from the reaction with lithium metal in hexane  

Microsoft Academic Search

The reaction of benzaldehyde with lithium metal was studied in two solvents and several temperatures as a model for more complex processes. Conditions were achieved to favor the adsorption of reactant on the metal surface, as well as to slow down diffusion of the reactive species to solution: reaction within adsorbed species produces benzyl benzoate in high yield.

N. Sbarbati Nudelman; Sara Mendiara

1997-01-01

91

Benzaldehyde lyase, a novel thiamine PPi-requiring enzyme, from Pseudomonas fluorescens biovar I.  

PubMed Central

Pseudomonas fluorescens biovar I can grow on benzoin as the sole carbon and energy source. This ability is due to benzaldehyde lyase, a new type of enzyme that irreversibly cleaves the acyloin linkage of benzoin, producing two molecules of benzaldehyde. Benzaldehyde lyase was purified 70-fold and found to require catalytic amounts of thiamine PPi (TPP) and a divalent cation as cofactors. Optimal activity was obtained with a 1.0 mM concentration of Mn2+, Mg2+, or Ca2+. Gel permeation chromatography indicated a native molecular weight of 80,000, whereas the enzyme migrated in sodium dodecyl sulfate-containing polyacrylamide gels as a single polypeptide with a molecular weight of 53,000. Benzaldehyde lyase is highly specific; of a variety of structurally related compounds tested, only benzoin and anisoin (4,4'-dimethoxybenzoin) acted as substrates, their apparent Kms being 9.0 x 10(-3) and 3.25 x 10(-2) mM, respectively. A catalytic mechanism for the enzyme is proposed. Images

Gonzalez, B; Vicuna, R

1989-01-01

92

FT-IR spectroscopy and DFT calculation study on the solvent effects of benzaldehyde in organic solvents  

NASA Astrophysics Data System (ADS)

FT-IR spectra of benzaldehyde in 11 different organic solvents were recorded and analyzed. The density functional theory (DFT) B3LYP/6-31G* method was chosen to calculate the infrared spectrum of benzaldehyde in gaseous state. The electrostatic effects of different solvents in benzaldehyde solutions were calculated using DFT with the self-consistent isodensity polarizable continuum model (SCI-PCM). Two remarkable carbonyl (C dbnd O) peaks of benzaldehyde were observed by FT-IR in alcohol solvents, which were caused by different hydrogen bond species and explained by ab initio calculation. The results showed that the combination of SCI-PCM model and ab initio calculation could give excellent agreements with FT-IR spectra of title compound in solutions.

Li, Yi; Zhang, Hui; Liu, Qing

2012-02-01

93

Defects in surface chemistry--reductive coupling of benzaldehyde on rutile TiO?(110).  

PubMed

The surface chemistry of oxygen and oxygenates on Rutile TiO2(110) is of great interest for various applications such as heterogeneous catalysis and photo catalysis. Though it is generally accepted that surface defects are active sites, the role of subsurface defects is under debate. We have therefore investigated the influence of the bulk defect density on the reductive coupling of benzaldehyde to stilbene as a model system. Using IRRAS we identify stilbene diolate as a reduction intermediate. The concentration of this intermediate is proportional to the bulk defect density, whereas adsorption of benzaldehyde at lower temperatures is not affected, which indicates a dominant role of Ti interstitials at temperatures above 400?K. PMID:24825761

Clawin, Peter M; Friend, Cynthia M; Al-Shamery, Katharina

2014-06-16

94

Proton transfer reactions between nitric acid and acetone, hydroxyacetone, acetaldehyde and benzaldehyde in the solid phase.  

PubMed

The heterogeneous and homogeneous reactions of acetone, hydroxyacetone, acetaldehyde and benzaldehyde with solid nitric acid (HNO(3)) films have been studied with Reflection-Absorption Infrared Spectroscopy (RAIRS) under Ultra-High Vacuum (UHV) conditions in the 90-170 K temperature range. In the bulk or at the surface of the films, nitric acid transfers its proton to the carbonyl function of the organic molecules, producing protonated acetone-H(+), hydroxyacetone-H(+), acetaldehyde-H(+) and benzaldehyde-H(+), and nitrate anions NO(3)(-), a reaction not observed when nitric acid is previously hydrated [J. Lasne, C. Laffon and Ph. Parent, Phys. Chem. Chem. Phys., 2012, 14, 697]. This provides a molecular-scale description of the carbonyl protonation reaction in an acid medium, the first step of the acid-catalyzed condensation of carbonyl compounds, fuelling the growth of secondary organic aerosols (SOA) in the atmosphere. PMID:23090634

Lasne, Jérôme; Laffon, Carine; Parent, Philippe

2012-12-01

95

Ortho-TMS Benzaldehyde: An Effective Linchpin for Type II Anion Relay Chemistry (ARC)  

PubMed Central

Ortho-TMS benzaldehyde, an effective bifunctional linchpin for Type II Anion Relay Chemistry (ARC), permits efficient multi-component union of a variety of nucleophiles and electrophiles, including the first example of a Pd-mediated ARC Type II process. To demonstrate the utility of the Type II ARC protocol, a “proof of concept” synthetic sequence was designed and implemented for construction of a focused library of “natural product-like” compounds.

Smith, Amos B.; Kim, Won-Suk; Wuest, William M.

2009-01-01

96

Biotransformation of benzaldehyde into ( R )-phenylacetylcarbinol by filamentous fungi or their extracts  

Microsoft Academic Search

Extracts of 14 filamentous fungi were examined regarding their potential for production of (R)-phenylacetylcarbinol [(R)-PAC], which is the chiral precursor in the manufacture of the pharmaceuticals ephedrine and pseudoephedrine. Benzaldehyde and pyruvate were transformed at a scale of 1.2 ml into PAC by cell-free extracts of all selected strains, covering the broad taxonomic spectrum of Ascomycota, Zygomycota and Basidiomycota. Highest

B. Rosche; V. Sandford; M. Breuer; B. Hauer; P. Rogers

2001-01-01

97

A new poly-substituted benzaldehyde from the leaves of Lysimachia fordiana Oliv.  

PubMed

A new poly-substituted benzaldehyde, 1, and a known compound quercetin (2) were isolated from the leaves of Lysimachia fordiana Oliv. The structure of compound 1, named fordianol, was determined as 2-heptyl-3,6-dihydroxy-4- methoxybenzaldehyde on the basis of spectroscopic methods. Fordianol did not inhibit the growth of SWO-38 (human brain neuroglioma), MCF-7 (human breast cancer) or HeLa (human cervical carcinoma) cell lines. PMID:17693959

Huang, Xin-an; Yang, Ren-zhou; Deng, Wen-di

2007-01-01

98

Benzaldehyde lyase-catalyzed diastereoselective C-C bond formation by simultaneous carboligation and kinetic resolution.  

PubMed

Enzymes create chiral microenvironments that may simultaneously generate several stereogenic centers in the same catalytic cycle, broadening the possibilities of biocatalysis. Benzaldehyde lyase (BAL) affords highly diastereoselective ?-hydroxy-ketones by simultaneously performing ligation and kinetic resolution of a racemic aldehyde. Thus, to the well-known enantioselective BAL-carboligation of aldehydes (C-C bond formation), another property, namely diastereoselectivity, is added in this paper for the first time. PMID:23280121

Müller, Christoph R; Pérez-Sánchez, María; Domínguez de María, Pablo

2013-03-28

99

Iron Chelators of the Di-2-pyridylketone Thiosemicarbazone and 2-Benzoylpyridine Thiosemicarbazone Series Inhibit HIV-1 Transcription: Identification of Novel Cellular Targets--Iron, Cyclin-Dependent Kinase (CDK) 2, and CDK9S?  

PubMed Central

HIV-1 transcription is activated by HIV-1 Tat protein, which recruits cyclin-dependent kinase 9 (CDK9)/cyclin T1 and other host transcriptional coactivators to the HIV-1 promoter. Tat itself is phosphorylated by CDK2, and inhibition of CDK2 by small interfering RNA, the iron chelator 2-hydroxy-1-naphthylaldehyde isonicotinoyl hydrazone (311), and the iron chelator deferasirox (ICL670) inhibits HIV-1 transcription. Here we have analyzed a group of novel di-2-pyridylketone thiosemicarbazone- and 2-benzoylpyridine thiosemicarbazone-based iron chelators that exhibit marked anticancer activity in vitro and in vivo (Proc Natl Acad Sci USA 103:7670–7675, 2006; J Med Chem 50:3716–3729, 2007). Several of these iron chelators, in particular 2-benzoylpyridine 4-allyl-3-thiosemicarbazone (Bp4aT) and 2-benzoylpyridine 4-ethyl-3-thiosemicarbazone (Bp4eT), inhibited HIV-1 transcription and replication at much lower concentrations than did 311 and ICL670. Neither Bp4aT nor Bp4eT were toxic after a 24-h incubation. However, longer incubations for 48 h or 72 h resulted in cytotoxicity. Analysis of the molecular mechanism of HIV-1 inhibition showed that the novel iron chelators inhibited basal HIV-1 transcription, but not the nuclear factor-?B-dependent transcription or transcription from an HIV-1 promoter with inactivated SP1 sites. The chelators inhibited the activities of CDK2 and CDK9/cyclin T1, suggesting that inhibition of CDK9 may contribute to the inhibition of HIV-1 transcription. Our study suggests the potential usefulness of Bp4aT or Bp4eT in antiretroviral regimens, particularly where resistance to standard treatment occurs.

Debebe, Zufan; Ammosova, Tatyana; Breuer, Denitra; Lovejoy, David B.; Kalinowski, Danuta S.; Karla, Pradeep K.; Kumar, Krishna; Jerebtsova, Marina; Ray, Patricio; Kashanchi, Fatah; Gordeuk, Victor R.; Richardson, Des R.

2011-01-01

100

Association of Polymorphisms in Odorant-Binding Protein Genes With Variation in Olfactory Response to Benzaldehyde in Drosophila  

PubMed Central

Adaptive evolution of animals depends on behaviors that are essential for their survival and reproduction. The olfactory system of Drosophila melanogaster has emerged as one of the best characterized olfactory systems, which in addition to a family of odorant receptors, contains an approximately equal number of odorant-binding proteins (OBPs), encoded by a multigene family of 51 genes. Despite their abundant expression, little is known about their role in chemosensation, largely due to the lack of available mutations in these genes. We capitalized on naturally occurring mutations (polymorphisms) to gain insights into their functions. We analyzed the sequences of 13 Obp genes in two chromosomal clusters in a population of wild-derived inbred lines, and asked whether polymorphisms in these genes are associated with variation in olfactory responsiveness. Four polymorphisms in 3 Obp genes exceeded the statistical permutation threshold for association with responsiveness to benzaldehyde, suggesting redundancy and/or combinatorial recognition by these OBPs of this odorant. Model predictions of alternative pre-mRNA secondary structures associated with polymorphic sites suggest that alterations in Obp mRNA structure could contribute to phenotypic variation in olfactory behavior.

Wang, Ping; Lyman, Richard F.; Shabalina, Svetlana A.; Mackay, Trudy F. C.; Anholt, Robert R. H.

2007-01-01

101

Association of polymorphisms in odorant-binding protein genes with variation in olfactory response to benzaldehyde in Drosophila.  

PubMed

Adaptive evolution of animals depends on behaviors that are essential for their survival and reproduction. The olfactory system of Drosophila melanogaster has emerged as one of the best characterized olfactory systems, which in addition to a family of odorant receptors, contains an approximately equal number of odorant-binding proteins (OBPs), encoded by a multigene family of 51 genes. Despite their abundant expression, little is known about their role in chemosensation, largely due to the lack of available mutations in these genes. We capitalized on naturally occurring mutations (polymorphisms) to gain insights into their functions. We analyzed the sequences of 13 Obp genes in two chromosomal clusters in a population of wild-derived inbred lines, and asked whether polymorphisms in these genes are associated with variation in olfactory responsiveness. Four polymorphisms in 3 Obp genes exceeded the statistical permutation threshold for association with responsiveness to benzaldehyde, suggesting redundancy and/or combinatorial recognition by these OBPs of this odorant. Model predictions of alternative pre-mRNA secondary structures associated with polymorphic sites suggest that alterations in Obp mRNA structure could contribute to phenotypic variation in olfactory behavior. PMID:17720903

Wang, Ping; Lyman, Richard F; Shabalina, Svetlana A; Mackay, Trudy F C; Anholt, Robert R H

2007-11-01

102

The Cytotoxicity of Benzaldehyde Nitrogen Mustard-2-Pyridine Carboxylic Acid Hydrazone Being Involved in Topoisomerase II? Inhibition  

PubMed Central

The antitumor property of iron chelators and aromatic nitrogen mustard derivatives has been well documented. Combination of the two pharmacophores in one molecule in drug designation is worth to be explored. We reported previously the syntheses and preliminary cytotoxicity evaluation of benzaldehyde nitrogen mustard pyridine carboxyl acid hydrazones (BNMPH) as extended study, more tumor cell lines (IC50 for HepG2: 26.1 ± 3.5??M , HCT-116: 57.5 ± 5.3??M, K562: 48.2 ± 4.0??M, and PC-12: 19.4 ± 2.2??M) were used to investigate its cytotoxicity and potential mechanism. In vitro experimental data showed that the BNMPH chelating Fe2+ caused a large number of ROS formations which led to DNA cleavage, and this was further supported by comet assay, implying that ROS might be involved in the cytotoxicity of BNMPH. The ROS induced changes of apoptosis related genes, but the TFR1 and NDRG1 metastatic genes were not obviously regulated, prompting that BNMPH might not be able to deprive Fe2+ of ribonucleotide reductase. The BNMPH induced S phase arrest was different from that of iron chelators (G1) and alkylating agents (G2). BNMPH also exhibited its inhibition of human topoisomerase II?. Those revealed that the cytotoxic mechanism of the BNMPH could stem from both the topoisomerase II inhibition, ROS generation and DNA alkylation.

Fu, Yun; Zhou, Sufeng; Liu, Youxun; Yang, Yingli; Sun, Xingzhi; Li, Changzheng

2014-01-01

103

Epr, cyclic voltammetric and biological activities of copper(II) complexes of salicylaldehyde N(4)-substituted thiosemicarbazone and heterocyclic bases  

Microsoft Academic Search

An interesting series of heterocyclic base adducts of copper(II) complexes have been synthesised by the reaction of copper(II) acetate with salicylaldehyde N(4)-phenylthiosemicarbazone in presence of heterocyclic bases like pyridine (py), piperidine (pip), ?\\/?-picoline (?\\/?-pic), 1,10-phenanthroline (phen) and 2,2?-bipyridine (bipy). IR, electronic, 1H and 13C NMR spectra of the thiosemicarbazone, as well as IR, electronic and EPR spectra of the complexes

Panampilly Bindu; Maliyeckal R. Prathapachandra Kurup; Thonduparambil R. Satyakeerty

1998-01-01

104

Crystal structure and photochromism of 1-phenyl-3-methyl-4-benzyl-5-one-pyrazole S-methyl thiosemicarbazone  

NASA Astrophysics Data System (ADS)

A new organic photochromic compound containing pyrazolone-ring photochromic functional unit: 1-phenyl-3-methyl-4-benzyl-5-one pyrazole S-methyl thiosemicarbazone (PMBP-smtsc) was synthesized. The photochromic properties and photochemical kinetics of PMBP-smtsc have been studied by UV reflectance spectra under irradiation of 365 nm light. The crystal structure analyses of photocolored product show the photochromism is due to the photoisomerization from enol form to keto form through an intermolecular proton transfer.

Liu, Lang; Jia, Dian-zeng; Ji, Ya-li; Yu, Kai-bei

2003-07-01

105

Catalytic features of a low-temperature reduced alumina-supported platinum catalyst. Activity and selectivity in the liquid-phase hydrogenation of benzaldehyde and nitrobenzene  

Microsoft Academic Search

A low-temperature reduced (LR) supported platinum catalyst was used for the hydrogenation of benzaldehyde, nitrobenzene and\\u000a their mixture in ethanol, and compared with a high-temperature reduced (HR) catalyst. For benzaldehyde the LR catalyst was\\u000a highly active to the formation of benzyl alcohol and did not give benzaldehyde diethyl acetal, which was largely formed by\\u000a the HR catalyst. For the mixture,

M. Arai; A. Obata; Y. Nishiyama

1997-01-01

106

Investigation of the spectroscopy and relaxation dynamics of benzaldehyde using molecular orbital calculations and laser ionization time-of-flight mass spectroscopy  

Microsoft Academic Search

Molecular orbital methods and laser ionization mass spectrometry measurements are used to investigate the spectroscopy and relaxation dynamics of benzaldehyde following excitation to its S2(\\/pi\\/pi\\/sp\\/*) state. Energies, equilibrium geometries and vibrational frequencies of ground and low-lying excited states of benzaldehyde neutral and cation determined by ab initio calculations provide a theoretical description of the electronic spectroscopy of benzaldehyde and of

Maria Cristina Rodrigues da Silva

1998-01-01

107

Controlled ligand deprotonation in lanthanide chelates with asymmetric semicarbazone/benzoylhydrazone or semicarbazone/thiosemicarbazone coordination spheres.  

PubMed

Asymmetric, potentially pentadentate ligands (H(2)L(3)) are formed by subsequent condensation of a semicarbazide and benzoylhydrazine on 2,6-diacetylpyridine. Two equivalents of H(2)L(3) reacts with CeCl(3).7H(2)O, Ce(SO(4))(2).4H(2)O, or EuCl(3).6H(2)O under formation of [Ln(III)(HL(3))(2)](+) cations (Ln = Ce, Eu) with exclusive deprotonation of the benzoylhydrazone ligand arms. The Ce(4+) ion of the sulfate salt is reduced during the reaction and forms 10-coordinate singly charged complex cations, the structure of which is identical to the product of the reaction of cerium(III) chloride. The exact position of deprotonation in the ligands is resolved by infrared spectroscopy, bond lengths considerations, and the hydrogen bonding in the solid-state structures of the products. A similar approach allows the synthesis of mixed semicarbazone/thiosemicarbazone ligands (H(2)L(4)). The reaction of H(2)L(4) with Sm(NO(3))(3).6H(2)O leads to the first structurally characterized lanthanide complex with thiosemicarbazone coordination. The solid-state structure of the 10-coordinate complex [Sm(HL(4))(2)]NO(3).H(2)O shows exclusive deprotonation of the thiosemicarbazone arms of the ligands. All isolated complexes are air stable and do not undergo ligand exchange reactions or hydrolysis in the presence of water. PMID:16060625

Jagst, Alexander; Sanchez, Agustin; Vazquez-Lopez, Ezequiel M; Abram, Ulrich

2005-08-01

108

Preparation and biodistribution studies of a radiogallium-acetylacetonate bis (thiosemicarbazone) complex in tumor-bearing rodents.  

PubMed

Various radiometal complexes have been developed for tumor imaging, especially Ga-68 tracer. In the present study, the development of a radiogallium bis-thiosemicarbazone complex has been reported. [(67)Ga] acetylacetonate bis(thiosemicarbazone) complex ([(67)Ga] AATS) was prepared starting [(67)Ga]Gallium acetate and freshly prepared acetylacetonate bis (thiosemicarbazone) (AATS) in 30 min at 90°C. The partition co-efficient and the stability of the tracer were determined in final solution (25°C) and the presence of human serum (37°C) up to 24 h. The biodistribution of the labeled compound in wild-type and fibrosarcoma-bearing rodents were determined up to 72 h. The radiolabled Ga complex was prepared in high radiochemical purity (> 97%, HPLC) followed by initial biodistribution data with the significant tumor accumulation of the tracer in 2 h which is far higher than free Ga-67 cation while the compound wash-out is significantly faster. Above-mentioned pharmacokinetic properties suggest an interesting radiogallium complex while prepared by the PET Ga radioisotope, (68)Ga, in accordance with the physical half life, for use in fibrosarcoma tumors, and possibly other malignancies. PMID:24250475

Jalilian, Amir Reza; Yousefnia, Hassan; Shafaii, Kamaleddin; Novinrouz, Aytak; Rajamand, Amir Abbas

2012-01-01

109

Preparation and Biodistribution Studies of a Radiogallium-Acetylacetonate Bis (Thiosemicarbazone) Complex in Tumor-Bearing Rodents  

PubMed Central

Various radiometal complexes have been developed for tumor imaging, especially Ga-68 tracer. In the present study, the development of a radiogallium bis-thiosemicarbazone complex has been reported. [67Ga] acetylacetonate bis(thiosemicarbazone) complex ([67Ga] AATS) was prepared starting [67Ga]Gallium acetate and freshly prepared acetylacetonate bis (thiosemicarbazone) (AATS) in 30 min at 90°C. The partition co-efficient and the stability of the tracer were determined in final solution (25°C) and the presence of human serum (37°C) up to 24 h. The biodistribution of the labeled compound in wild-type and fibrosarcoma-bearing rodents were determined up to 72 h. The radiolabled Ga complex was prepared in high radiochemical purity (> 97%, HPLC) followed by initial biodistribution data with the significant tumor accumulation of the tracer in 2 h which is far higher than free Ga-67 cation while the compound wash-out is significantly faster. Above-mentioned pharmacokinetic properties suggest an interesting radiogallium complex while prepared by the PET Ga radioisotope, 68Ga, in accordance with the physical half life, for use in fibrosarcoma tumors, and possibly other malignancies.

Jalilian, Amir Reza; Yousefnia, Hassan; Shafaii, Kamaleddin; Novinrouz, Aytak; Rajamand, Amir Abbas

2012-01-01

110

Enhanced Benzaldehyde Tolerance in Zymomonas mobilis Biofilms and the Potential of Biofilm Applications in Fine-Chemical Production  

PubMed Central

Biotransformation plays an increasingly important role in the industrial production of fine chemicals due to its high product specificity and low energy requirement. One challenge in biotransformation is the toxicity of substrates and/or products to biocatalytic microorganisms and enzymes. Biofilms are known for their enhanced tolerance of hostile environments compared to planktonic free-living cells. Zymomonas mobilis was used in this study as a model organism to examine the potential of surface-associated biofilms for biotransformation of chemicals into value-added products. Z. mobilis formed a biofilm with a complex three-dimensional architecture comprised of microcolonies with an average thickness of 20 ?m, interspersed with water channels. Microscopic analysis and metabolic activity studies revealed that Z. mobilis biofilm cells were more tolerant to the toxic substrate benzaldehyde than planktonic cells were. When exposed to 50 mM benzaldehyde for 1 h, biofilm cells exhibited an average of 45% residual metabolic activity, while planktonic cells were completely inactivated. Three hours of exposure to 30 mM benzaldehyde resulted in sixfold-higher residual metabolic activity in biofilm cells than in planktonic cells. Cells inactivated by benzaldehyde were evenly distributed throughout the biofilm, indicating that the resistance mechanism was different from mass transfer limitation. We also found that enhanced tolerance to benzaldehyde was not due to the conversion of benzaldehyde into less toxic compounds. In the presence of glucose, Z. mobilis biofilms in continuous cultures transformed 10 mM benzaldehyde into benzyl alcohol at a steady rate of 8.11 g (g dry weight)?1 day?1 with a 90% molar yield over a 45-h production period.

Li, Xuan Zhong; Webb, Jeremy S.; Kjelleberg, Staffan; Rosche, Bettina

2006-01-01

111

Derivatives  

NSDL National Science Digital Library

Murray Bourne developed the Interactive Mathematics site while working as a mathematics lecturer at Ngee Ann Polytechnic in Singapore. The site contains numerous mathematics tutorials and resources for students and teachers alike. This specific page is focused on differentiation, or finding derivatives. Bourne walks users through an introduction to differentiation and limits, and then moves on to more specific applications like rate of change, derivatives of polynomials, and differentiating powers of a function. Each topic includes graphs and interactive materials designed to aid users in understanding the presented concepts. The information here is presented in a clear, straightforward manner that is appropriate for introductory and advanced calculus students alike.

Bourne, Murray

2008-04-22

112

Derivate  

NSDL National Science Digital Library

In this activity, students input functions in order to calculate the derivative and tangent line of that function. This activity allows students to explore tangent lines of various functions. This activity includes supplemental materials, including background information about the topics covered, a description of how to use the application, and exploration questions for use with the java applet.

2010-01-01

113

Synthesis and characterization of indium(III) complexes with tri- and pentadentate thiosemicarbazones. Crystal and molecular structure of [InCl 2(HDAPTSC)] · 2 DMSO, {O[In(HDAPTSC)(OH)] 2} · 5MeOH, [InCl 2(APTSC)(MeOH)], [In(APTSC) 2]PF 6 and (H 2APTSC)][InCl(APTSC)(mnt)] · 0.5 H 2O (H 2DAPTSC = 2,6-diacetylpyridine-bis(thiosemicarbazone), HAPTSC = 2-acetylpyridine-thiosemicarbazone, mnt 2 = 1,2-dicyanoethene-1,2-dithiolate)  

Microsoft Academic Search

The synthesis and characterization of novel indium(III) complexes with pyridine-thiosemicarbazone ligands are reported as well as ligand exchange reactions on the products. 2,6-Diacetylpyridine-bis(thiosemicarbazone), C5H3N(C3N3SH6)2 (H2DAPTSC), and 2-acetylpyridine-thiosemicarbazone, C5H4N(C3N3SH6) (HAPTSC), were reacted with indium(III) halides and indium(III) nitrate, respectively, to give [InX2(HDAPTSC)], {O[In(HDAPTSC)(OH)]2}, [InX2(APTSC)(MeOH)] and [In(APTSC)2]PF6.

Sonja Abram; Cäcilia Maichle-Mössmer; Ulrich Abram

1998-01-01

114

fac-Bromidotricarbonyl[2-(diisopropylphosphanyl)benzaldehyde-?2 O,P]rhenium(I)  

PubMed Central

The structure of the title complex, [ReBr(C13H19OP)(CO)3], displays a facial coordination of the three CO ligands and a ?2 O,P coordination mode of the 2-diisopropyl­phosphino­benzaldehyde ligands. The Re—C bond distance for the CO ligand trans to the P atom is, due to its trans influence, elongated to 1.943?(3)?Å, showing that this CO ligand is more weakly bound to the Re centre than the other two.

Apostolidis, Christos; Ahlmann, Martin; Walter, Olaf

2012-01-01

115

Molecular characterization of benzyl alcohol dehydrogenase and benzaldehyde dehydrogenase II of Acinetobacter calcoaceticus.  

PubMed Central

The nucleotide sequences of xylB and xylC from Acinetobacter calcoaceticus, the genes encoding benzyl alcohol dehydrogenase and benzaldehyde dehydrogenase II, were determined. The complete nucleotide sequence indicates that these two genes form part of an operon and this was supported by heterologous expression and physiological studies. Benzaldehyde dehydrogenase II is a 51654 Da protein with 484 amino acids per subunit and it is typical of other prokaryotic and eukaryotic aldehyde dehydrogenases. Benzyl alcohol dehydrogenase has a subunit Mr of 38923 consisting of 370 amino acids, it stereospecifically transfers the proR hydride of NADH, and it is a member of the family of zinc-dependent long-chain alcohol dehydrogenases. The enzyme appears to be more similar to animal and higher-plant alcohol dehydrogenases than it is to most other microbial alcohol dehydrogenases. Residue His-51 of zinc-dependent alcohol dehydrogenases is thought to be necessary as a general base for catalysis in this category of alcohol dehydrogenases. However, this residue was found to be replaced in benzyl alcohol dehydrogenase from A. calcoaceticus by an isoleucine, and the introduction of a histidine residue in this position did not alter the kinetic coefficients, pH optimum or substrate specificity of the enzyme. Other workers have shown that His-51 is also absent from the TOL-plasmid-encoded benzyl alcohol dehydrogenase of Pseudomonas putida and so these two closely related enzymes presumably have a catalytic mechanism that differs from that of the archetypal zinc-dependent alcohol dehydrogenases.

Gillooly, D J; Robertson, A G; Fewson, C A

1998-01-01

116

Benzoxyl radical decomposition kinetics: formation of benzaldehyde + H, phenyl + CH2O, and benzene + HCO.  

PubMed

The kinetics of benzoxyl radical decomposition was studied using ab initio computational chemistry and RRKM rate theory. The benzoxyl radical is an important but short-lived intermediate in the combustion of toluene and other alkylated aromatic hydrocarbons. A theoretical study of the thermochemistry and kinetics to products over a range of temperatures and pressures for benzoxyl decomposition is reported. Ab initio calculations with the G3X theoretical method reveal low-energy pathways from the benzoxyl radical to benzaldehyde + H and the phenyl radical + formaldehyde (CH(2)O), as well as a novel mechanism to benzene + the formyl radical (HC(*)O). RRKM simulations were performed for benzoxyl decomposition as a function of temperature and pressure. Benzaldehyde formation constitutes more than 80% of the total reaction products at temperatures below 1000 K, decreasing to around 50% at 2000 K. Formation of benzene + HC(*)O and phenyl + CH(2)O is of similar importance, each accounting for 5-10% of the decomposition products at around 1000 K, increasing to 20-30% at 2000 K. The results presented here should lead to improved kinetic models for the oxidation of alkylated aromatic hydrocarbons, particularly for the formation of benzene as a direct oxidation product of toluene. Re-evaluation of the phenyl radical heat of formation leads us to suggest a benzene C-H bond dissociation energy in the range of 113.5-114.5 kcal mol(-1). PMID:19496593

da Silva, Gabriel; Bozzelli, Joseph W

2009-06-25

117

Thiosemicarbazones of formyl benzoic acids as novel potent inhibitors of estrone sulfatase.  

PubMed

Thiosemicarbazones of the microbial metabolite madurahydroxylactone, a polysubstituted benzo[a]naphthacenequinone, have been previously reported by us as potent nonsteroidal inhibitors of the enzyme estrone sulfatase (cyclohexylthiosemicarbazone 1, IC50 0.46 microM). The active pharmacophore of 1 has now been identified to be 2-formyl-6-hydroxybenzoic acid cyclohexylthiosemicarbazone (25, IC50 4.2 microM). The active partial structure was derivatized in the search for novel agents against hormone-dependent breast cancer. Further substantial increases in activity were achieved by reversal of functional groups leading to the cyclohexylthiosemicarbazones of 5-formylsalicylic acid (35, IC50 0.05 microM) and 3-formylsalicylic acid (34, IC50 0.15 microM) as the most potent analogues identified to date. Both compounds were shown to be noncompetitive inhibitors of estrone sulfatase with Ki values of 0.13 microM and 0.12 microM, respectively. The compounds showed low acute toxicity in the hen's fertile egg screening test. PMID:17580843

Jütten, Peter; Schumann, Winfried; Härtl, Albert; Dahse, Hans-Martin; Gräfe, Udo

2007-07-26

118

Conformation and coordination of 1-phenyl-3-methyl-4-benzal-5-pyrazolone thiosemicarbazone: A density functional study  

NASA Astrophysics Data System (ADS)

Density functional theory method has been employed to study the molecular properties of four tautomers and their deprotonated species of 1-phenyl-3-methyl-4-benzal-5-pyrazolone thiosemicarbazone. The solvent effect has been investigated by applying the polarizable continuum model of the self-consistent reaction field theory. The condensed Fukui functions have been calculated to assess the relative reactivity of different sites in the ligands. Molecular electrostatic potential is obtained as an additional molecular descriptor for revealing the regions of the molecular species to which an electrophile would initially be attracted.

Wu, Dongling; Jia, Dianzeng; Liu, Lang; Liu, Anjie

119

Targeting triple negative breast cancer cells by N3-substituted 9,10-phenanthrenequinone thiosemicarbazones and their metal complexes.  

PubMed

Novel N(3)-substituted 9,10-Phenanthrenequinone thiosemicarbazones and their copper, nickel and palladium complexes are structurally characterized and reported along with the single crystal X-ray structures of three ligands and one nickel complex. All compounds were evaluated for their antiproliferative potential against Triple Negative Breast Cancer (TNBC) cells which have poor prognosis and no effective drugs to treat with. All compounds exhibited antiproliferative activity against these cells. Among the metal complexes evaluated, redox active copper complexes were found to be more potent. The possible mechanism for such enhanced activity can be attributed to the generation of oxidative stress, which was amenable for targeting through metal complexation. PMID:23770498

Afrasiabi, Zahra; Stovall, Preston; Finley, Kristen; Choudhury, Amitava; Barnes, Charles; Ahmad, Aamir; Sarkar, Fazlul; Vyas, Alok; Padhye, Subhash

2013-10-01

120

Syntheses, structural and spectral studies of six-coordinate, [Ph 2SnCl(acpm)], and seven-coordinate, [ nBu 2Sn(dapm)], diorganotin(IV) complexes with N, N, S-tridentate and S, N, N, N, S-pentadentate N4-heterocyclic thiosemicarbazones  

NASA Astrophysics Data System (ADS)

The reaction of the N, N, S-tridentate ligand 2-acetylpyridine ( N4-morpholyl thiosemicarbazones), Hacpm, with Ph 2SnCl 2 leads to the formation of the six-coordinate complex [Ph 2SnCl(acpm)] ( 1), whereas the reaction of the S, N, N, N, S-pentadentate ligand 2,6-diacetylpyridine bis( N4-morpholyl thiosemicarbazone), H 2dapm, with nBu 2SnCl 2 leads to the formation of the seven-coordinate complex [ nBu 2Sn(dapm)] ( 2). Both compounds were studied by microanalyses, IR, NMR ( 1H, 13C, 119Sn) and Mössbauer spectroscopy to investigate their structural properties. The organotin(IV) complexes were also studied by single crystal X-ray diffraction and the structure determination revealed that the phenyl derivative crystallizes in the triclinic space group (P1¯) as discrete neutral molecules, with the tin(IV) ion in a distorted octahedral geometry with the acpm 1- ligand in a meridional configuration and the phenyl groups in trans positions. X-ray analysis shows that the n-butyl complex crystallizes in the monoclinic space group ( P2 1/ c) as discrete neutral complexes, with the tin(IV) ion in a distorted pentagonal bipyramidal geometry. A correlation between Mössbauer and X-ray data based on the point-charge model is discussed.

de Sousa, Gerimário F.; Manso, Luís Carlos C.; Lang, Ernesto S.; Gatto, Claudia C.; Mahieu, Bernard

2007-01-01

121

Reactions of Supercritical Water with Benzaldehyde, Benzylidenebenzylamine, Benzyl Alcohol, and Benzoic Acid. (Reannouncement with New Availability Information).  

National Technical Information Service (NTIS)

This paper describes the results of reactions of benzaldehyde, benzyl alcohol, benzoic acid, and benzylidenebenzylamine (C6H5CH2N=CHC6H5) With supercritical water (SW) since these compounds were determined or assumed to be major intermediates in the react...

C. C. Tsao Y. Zhou X. Liu T. J. Huser

1992-01-01

122

Chemical reactivity and skin sensitization potential for benzaldehydes: can Schiff base formation explain everything?  

PubMed

Skin sensitizers chemically modify skin proteins rendering them immunogenic. Sensitizing chemicals have been divided into applicability domains according to their suspected reaction mechanism. The widely accepted Schiff base applicability domain covers aldehydes and ketones, and detailed structure-activity-modeling for this chemical group was presented. While Schiff base formation is the obvious reaction pathway for these chemicals, the in silico work was followed up by limited experimental work. It remains unclear whether hydrolytically labile Schiff bases can form sufficiently stable epitopes to trigger an immune response in the living organism with an excess of water being present. Here, we performed experimental studies on benzaldehydes of highly differing skin sensitization potential. Schiff base formation toward butylamine was evaluated in acetonitrile, and a detailed SAR study is presented. o-Hydroxybenzaldehydes such as salicylaldehyde and the oakmoss allergens atranol and chloratranol have a high propensity to form Schiff bases. The reactivity is highly reduced in p-hydroxy benzaldehydes such as the nonsensitizing vanillin with an intermediate reactivity for p-alkyl and p-methoxy-benzaldehydes. The work was followed up under more physiological conditions in the peptide reactivity assay with a lysine-containing heptapeptide. Under these conditions, Schiff base formation was only observable for the strong sensitizers atranol and chloratranol and for salicylaldehyde. Trapping experiments with NaBH?CN showed that Schiff base formation occurred under these conditions also for some less sensitizing aldehydes, but the reaction is not favored in the absence of in situ reduction. Surprisingly, the Schiff bases of some weaker sensitizers apparently may react further to form stable peptide adducts. These were identified as the amides between the lysine residues and the corresponding acids. Adduct formation was paralleled by oxidative deamination of the parent peptide at the lysine residue to form the peptide aldehyde. Our results explain the high sensitization potential of the oakmoss allergens by stable Schiff base formation and at the same time indicate a novel pathway for stable peptide-adduct formation and peptide modifications by aldehydes. The results thus may lead to a better understanding of the Schiff base applicability domain. PMID:22950880

Natsch, Andreas; Gfeller, Hans; Haupt, Tina; Brunner, Gerhard

2012-10-15

123

Synthesis and structure-activity evaluation of isatin-?-thiosemicarbazones with improved selective activity towards multidrug-resistant cells expressing P-glycoproteina  

PubMed Central

Cancer multidrug resistance (MDR) mediated by ATP-binding cassette (ABC) transporters presents a significant unresolved clinical challenge. One strategy to resolve MDR is to develop compounds that selectively kill cells over-expressing the efflux transporter P-glycoprotein (MDR1, P-gp, ABCB1). We have previously reported structure-activity studies based around the lead compound NSC73306 (1, 1-isatin-4-(4?-methoxyphenyl)-3-thiosemicarbazone, 4.3-fold selective). Here we sought to extend this work on MDR1-selective analogs by establishing whether 1 showed ‘robust’ activity against a range of cell lines expressing P-gp. We further aimed to synthesize and test analogs with varied substitution at the N4-position, and substitution around the N4-phenyl ring of isatin-?-thiosemicarbazones (IBTs), to identify compounds with increased MDR1-selectivity. Compound 1 demonstrated MDR1-selectivity against all P-gp-expressing cell lines examined. This selectivity was reversed by inhibitors of P-gp ATPase activity. Structural variation at the 4?-phenyl position of 1 yielded compounds of greater MDR1-selectivity. Two of these analogs, 1-isatin-4-(4?-nitrophenyl)-3-thiosemicarbazone (22, 8.3-fold selective) and 1-isatin-4-(4?-tert-butyl phenyl)-3-thiosemicarbazone (32, 14.8-fold selective), were selected for further testing, and were found to retain the activity profile of 1. These compounds are the most active IBTs identified to date.

Hall, Matthew D.; Brimacombe, Kyle R.; Varonka, Matthew S.; Pluchino, Kristen M.; Monda, Julie K.; Li, Jiayang; Walsh, Martin J.; Boxer, Matthew B.; Warren, Timothy H.; Fales, Henry M.; Gottesman, Michael M.

2011-01-01

124

4-{2-[2-(4-Formyl-phen-oxy)eth-oxy]eth-oxy}benzaldehyde.  

PubMed

The title compound, C(18)H(18)O(5), was obtained by the reaction of 4-hy-droxy-benzaldehyde with bis-(2,2-dichloro-eth-yl) ether in dimethyl-formamide. In the crystal, the mol-ecule lies on a twofold rotation axis that passes through the central O atom of the aliphatic chain, thus leading to one half-mol-ecule being present per asymmetric unit. The carbonyl, aryl and O-CH(2)-CH(2) groups are almost coplanar, with an r.m.s. deviation of 0.030?Å. The aromatic rings are approximately perpendicular to each other, forming a dihedral angle of 78.31?sh;H?O hydrogen bonds and C-H?? inter-actions help to consolidate the three-dimensional network. PMID:21754870

Ma, Zhen; Cao, Yiqun

2011-06-01

125

Electronic excitation energies, three-state intersections, and photodissociation mechanisms of benzaldehyde and acetophenone  

NASA Astrophysics Data System (ADS)

We report a theoretical study on the electronically excited states and the mechanisms of photodissociation of C6H5CHO and C6H5COCH3. For both molecules, we find an S1/T2/T1 three-state intersection region, which allows for an efficient S1 ? T1 intersystem crossing via the T2 state that acts as a relay. Consequently, T1 reactions become the major radical photodissociation channels. According to the computed energy profiles, T1 photodissociation mainly yields phenyl and formyl radicals in the case of benzaldehyde, and benzoyl and methyl radicals in the case of acetophenone, with different C-C bonds being cleaved preferentially. The computational results agree well with the available experimental data.

Cui, Ganglong; Lu, You; Thiel, Walter

2012-06-01

126

Potential mechanism of the anti-trypanosomal activity of organoruthenium complexes with bioactive thiosemicarbazones.  

PubMed

In the search for new metal-based drugs against diseases produced by trypanosomatid parasites, four organoruthenium(II) compounds [Ru2(p-cymene)2(L)2]X2, where L are bioactive 5-nitrofuryl-containing thiosemicarbazones and X?=?Cl or PF6, had been previously obtained. These compounds had shown activity on Trypanosoma brucei, the etiological agent of African trypanosomiasis. Because of genomic similarities between trypanosomatides, these ruthenium compounds were evaluated, in the current work, on Trypanosoma cruzi, the parasite responsible of American trypanosomiasis (Chagas disease). Two of them showed significant in vitro growth inhibition activity against the infective trypomastigote form of T. cruzi (Dm28c clone, IC50?=?11.69 and 59.42 ?M for [Ru2(p-cymene)2(L4)2]Cl2 and [Ru2(p-cymene)2(L1)2]Cl2, respectively, where HL4?=?5-nitrofuryl-N-phenylthiosemicarbazone and HL1?=?5-nitrofurylthiosemicarbazone), showing fairly good selectivities toward trypanosomes with respect to mammalian cells (J774 murine macrophages). Moreover, [Ru2(p-cymene)2(L2)2]Cl2, where HL2?=?5-nitrofuryl-N-methylthiosemicarbazone, was synthesized in order to evaluate the effect of improved solubility on biological behavior. This new chloride salt showed higher activity against T. cruzi than that of the previously synthesized hexafluorophosphate one (Dm28c clone, IC50?=?14.30 ?M for the former and 231.3 ?M for the latter). In addition, the mode of antitrypanosomal action of the organoruthenium compounds was investigated. The complexes were not only able to generate toxic free radicals through bioreduction but they also interacted with two further potential parasite targets: DNA and cruzipain, a cysteine protease which plays a fundamental role in the biological cycle of these parasites. The results suggest a "multi-target" mechanism of trypanosomicidal action for the obtained complexes. PMID:23564472

Demoro, Bruno; Rossi, Miriam; Caruso, Francesco; Liebowitz, Daniel; Olea-Azar, Claudio; Kemmerling, Ulrike; Maya, Juan Diego; Guiset, Helena; Moreno, Virtudes; Pizzo, Chiara; Mahler, Graciela; Otero, Lucía; Gambino, Dinorah

2013-06-01

127

Evaluation of the Anti-Schistosoma mansoni Activity of Thiosemicarbazones and Thiazoles  

PubMed Central

Schistosomiasis is a chronic and debilitating disease caused by a trematode of the genus Schistosoma and affects over 207 million people. Chemotherapy is the only immediate recourse for minimizing the prevalence of this disease and involves predominately the administration of a single drug, praziquantel (PZQ). Although PZQ has proven efficacy, there is a recognized need to develop new drugs as schistosomicides since studies have shown that repeated use of this drug in areas of endemicity may cause a temporary reduction in susceptibility in isolates of Schistosoma mansoni. Hydrazones, thiosemicarbazones, phthalimides, and thiazoles are thus regarded as privileged structures used for a broad spectrum of activities and are potential candidates for sources of new drug prototypes. The present study determined the in vitro schistosomicidal activity of 10 molecules containing these structures. During the assays, parameters such motility and mortality, oviposition, morphological changes in the tegument, cytotoxicity, and immunomodulatory activity caused by these compounds were evaluated. The results showed that compounds formed of thiazole and phthalimide led to higher mortality of worms, with a significant decline in motility, inhibition of pairing and oviposition, and a mortality rate of 100% starting from 144 h of exposure. These compounds also stimulated the production of nitric oxide and tumor necrosis factor alpha (TNF-?), thereby demonstrating the presence of immunomodulatory activity. The phthalyl thiazole LpQM-45 caused significant ultrastructural alterations, with destruction of the tegument in both male and female worms. According to the present study, phthalyl thiazole compounds possess antischistosomal activities and should form the basis for future experimental and clinical trials.

de Oliveira, Sheilla Andrade; de Oliveira Filho, Gevanio Bezerra; Moreira, Diogo Rodrigo Magalhaes; Gomes, Paulo Andre Teixeira; da Silva, Anekecia Lauro; de Barros, Andreia Ferreira; da Silva, Aline Caroline; dos Santos, Thiago Andre Ramos; Pereira, Valeria Rego Alves; Goncalves, Gabriel Gazzoni Araujo; Brayner, Fabio Andre; Alves, Luiz Carlos; Wanderley, Almir Goncalves; Leite, Ana Cristina Lima

2014-01-01

128

Synthesis, spectroscopic characterization, structural studies and antibacterial and antitumor activities of diorganotin complexes with 3-methoxysalicylaldehyde thiosemicarbazone  

NASA Astrophysics Data System (ADS)

Three organotin(IV) complexes, Ph2Sn(mstsc) (1), Me2Sn(mstsc) (2) and Bu2Sn(mstsc) (3), have been synthesized from reaction of R2SnCl2 (R = Ph, Me and Bu) with 3-methoxysalicylaldehyde thiosemicarbazone (H2mstsc). The synthesized complexes have been characterized by elemental analysis and FT-IR, 1H, 13C and 119Sn NMR spectroscopy. The structures of 2 and 3 have been also confirmed by X-ray crystallography. On the basis of spectral and structural data thiosemicarbazone acts as a tridentate dianionic ligand and coordinates to tin through phenolic oxygen, the azomethine nitrogen and thiolate sulfur atoms. The metal coordination geometry for 2 and 3 is described as distorted square pyramid and the crystal lattices are stabilized by intermolecular hydrogen bands. On the basis of 119Sn NMR data, coordination number of tin retains five in solution. The in vitro antibacterial activity of ligand and its complexes has been evaluated against one Gram-positive and three Gram-negative bacteria. Complex 2 exhibited good activity along with the standard antibacterial drugs. The in vitro cytotoxicities of the synthesized compounds against Jurkat cells were evaluated by the standard WST-1 assay. The activity decreases in the order 3 > 1 > 2 = H2mstsc.

Khandani, Marzieh; Sedaghat, Tahereh; Erfani, Nasrollah; Haghshenas, Mohammad Reza; Khavasi, Hamid Reza

2013-04-01

129

Nickel(II) Complex of Polyhydroxybenzaldehyde N4-Thiosemicarbazone Exhibits Anti-Inflammatory Activity by Inhibiting NF-?B Transactivation  

PubMed Central

Background The biological properties of thiosemicarbazone have been widely reported. The incorporation of some transition metals such as Fe, Ni and Cu to thiosemicarbazone complexes is known to enhance its biological effects. In this study, we incorporated nickel(II) ions into thiosemicarbazone with N4-substitution groups H3L (H; H3L1, CH3; H3L2, C6H5; H3L3 and C2H5; H3L4) and examined its potential anti-inflammatory activity. Methodology/Principal Findings Four ligands (1–4) and their respective nickel-containing complexes (5–8) were synthesized and characterized. The compounds synthesized were tested for their effects on NF-?B nuclear translocation, pro-inflammatory cytokines secretion and NF-?B transactivation activity. The active compound was further evaluated on its ability to suppress carrageenan-induced acute inflammation in vivo. A potential binding target of the active compound was also predicted by molecular docking analysis. Conclusions/Significance Among all synthesized compounds tested, we found that complex [Ni(H2L1)(PPh3)]Cl (5) (complex 5), potently inhibited I?B? degradation and NF-?B p65 nuclear translocation in LPS-stimulated RAW264.7 cells as well as TNF?-stimulated HeLa S3 cells. In addition, complex 5 significantly down-regulated LPS- or TNF?-induced transcription of NF-?B target genes, including genes that encode the pro-inflammatory cytokines TNF?, IFN? and IL6. Luciferase reporter assays confirmed that complex 5 inhibited the transactivation activity of NF-?B. Furthermore, the anti-inflammatory effect of complex 5 was also supported by its suppressive effect on carrageenan-induced paw edema formation in wild type C57BL/6 mice. Interestingly, molecular docking study showed that complex 5 potentially interact with the active site of IKK?. Taken together, we suggest complex 5 as a novel NF-?B inhibitor with potent anti-inflammatory effects.

Loh, Sheng Wei; Looi, Chung Yeng; Hassandarvish, Pouya; Phan, Alicia Yi Ling; Wong, Won Fen; Wang, Hao; Paterson, Ian C.; Ea, Chee Kwee; Mustafa, Mohd Rais; Maah, Mohd Jamil

2014-01-01

130

Decrease in ovalbumin-induced pulmonary allergic response by benzaldehyde but not acetaldehyde exposure in a Guinea pig model.  

PubMed

The pulmonary effects of two environmentally relevant aldehydes were investigated in nonsensitized or ovalbumin (OA)-sensitized guineapigs (GPs). Four-week-old male Hartley GPs, weighing about 400 g, were intraperitoneally injected with 1 ml of an NaCl solution containing 100 microg OA and 100 mg Al(OH)(3). They were then exposed to either acetaldehyde (200 ppb) or benzaldehyde (500 ppb) for 4 wk (6 h/d, 5 d/wk). At the end of exposure, GPs were challenged with an OA aerosol (0.1% in NaCl) and pulmonary functions were measured. The day after, guinea pigs were anesthetized and several endpoints related to inflammatory and allergic responses were assessed in blood, whole-lung histology, and bronchoalveolar lavage (BAL). Sensitized nonexposed GPs showed bronchial hyperresponsiveness to OA and an increased number of eosinophils in blood and BAL, together with a rise in total protein and leukotrienes (LTB(4) and LTC(4)/D(4)/E(4)) in BAL. In nonsensitized GPs, exposure to acetaldehyde or benzaldehyde did not induce any change in the tested parameters, with the exception of irritation of the respiratory tract as detected by histology and an increased number of alveolar macrophages in animals exposed to acetaldehyde. In sensitized GPs, exposure to acetaldehyde induced a moderate irritation of the respiratory tract but no change in biological parameters linked to the inflammatory and allergic responses. In contrast, exposure to benzaldehyde induced a decrease both in OA-induced bronchoconstriction and in eosinophil and neutrophil numbers in BAL, an increase in the bronchodilatator mediator prostaglandin E(2) (PGE(2)), and a decrease in the bronchoconstrictor mediators LTC(4)/D(4)/E(4). Further investigations are needed to determine if the attenuated response observed in sensitized GPs exposed to benzaldehyde is due to an alteration of the mechanism of sensitization or to a more direct effect on various mechanisms of the allergic response. PMID:12133233

Lacroix, G; Tissot, S; Rogerieux, F; Beaulieu, R; Cornu, L; Gillet, C; Robidel, F; Lefèvre, J P; Bois, F Y

2002-07-26

131

Solid-state proton transfer studies on phototautomerization of 1-phenyl-3-methyl-4-furoyl-5-pyrazolone 4-methyl thiosemicarbazone  

NASA Astrophysics Data System (ADS)

A novel keto-enol phototautomeric compound of 1-phenyl-3-methyl-4-(-furoyl)-5-pyrazolone 4-methyl thiosemicarbazone was found to undergo phototautomerization in the crystalline state. The reaction rate constant was studied based on the first-order kinetics curve. Crystal structural analysis and theoretical calculations show that the pyrazolone ring stabilizes in the keto form. The conclusion can be made that its phototautomerization in the crystalline state is associated with a photo-induced intermolecular double-proton-transfer reaction along intermolecular hydrogen bonds N sbnd H⋯O and S⋯H sbnd N leading to a colored tautomer as the compound crystallizes in a hydrogen bonded supramolecular configuration.

Zhang, Tao; Liu, Guangfei; Liu, Lang; Jia, Dianzeng; Zhang, Li

2006-08-01

132

Crystal structures of 5-Bromo-2-hydroxybenzaldehyde, 2-hydroxy-3-methoxybenzaldehyde, and 2-hydroxynaphthalene-1-carbaldehyde 4-(2-pyridyl) thiosemicarbazones  

NASA Astrophysics Data System (ADS)

5-Bromo-2-hydroxybenzaldehyde, 2-hydroxy-3-methoxybenzaldehyde, and 2-hydroxynaphthalene-1-carbaldehyde 4-(2-pyridyl) thiosemicarbazones ( I-III, respectively) were synthesized and their crystal structures were determined by X-ray diffraction. All these molecules are almost planar. The presence of bulky substituents at the terminal nitrogen atoms of these molecules does not lead to changes in the conformation of the thiosemicarbazide moiety. Depending on the nature of substituents in the phenol rings, the crystals are composed of either centrosymmetric dimers ( I) or infinite chains ( II and III). In the concentration range of 10-5-10-7 mol/L, thiosemicarbazones I-III selectively inhibit the growth of human myeloid leukemia HL60 cells.

Chumakov, Yu. M.; Petrenko, P. A.; Codita, T. B.; Tsapkov, V. I.; Poirier, D.; Gulea, A. P.

2014-03-01

133

Synthesis, antioxidant activities of the nickel(II), iron(III) and oxovanadium(IV) complexes with N2O2 chelating thiosemicarbazones  

NASA Astrophysics Data System (ADS)

The nickel(II), iron(III) and oxovanadium(IV) complexes of the N2O2 chelating thiosemicarbazones were synthesized using 4-hydroxysalicyladehyde-S-methylthiosemicarbazone and R1-substitute-salicylaldehyde (R1: 4-OH, H) in the presence of Ni(II), Fe(III), VO(IV) ions by the template reaction. The structures of the thiosemicarbazone complexes were characterized by FT-IR, 1H NMR, elemental, ESI-MS and APCI-MS analysis. The synthesized compounds were screened for their antioxidant capacity by using the cupric reducing antioxidant capacity (CUPRAC) method. Trolox equivalent antioxidant capacity (TEAC) of iron(III) complex, 1c, was measured to be higher than that of the other complexes. Other parameters of antioxidant activity (scavenging effects on rad OH, O2rad - and H2O2) of these compounds were also determined. All the compounds have shown encouraging ROS scavenging activities.

Bal-Demirci, Tülay; ?ahin, Musa; Özyürek, Mustafa; Kondakç?, Esin; Ülküseven, Bahri

134

Synthesis, crystal structure, characterization of zinc(II), cadmium(II) complexes with 3-thiophene aldehyde thiosemicarbazone (3TTSCH). Biological activities of 3TTSCH and its complexes.  

PubMed

The reaction of zinc(II) chloride, cadmium(II) chloride and bromide with 3-thiophene aldehyde thiosemicarbazone leads to the formation of a series of new complexes. They have been characterized by spectroscopic studies: infrared, (1)H NMR, and electronic spectra. The crystal structures of the compound [ZnCl(2)(3TTSCH)(2)] and [CdBr(2)(3TTSCH)(2)] have been determined by X-ray diffraction methods. For the complexes [ZnCl(2)(3TTSCH)(2)] and [CdBr(2)(3TTSCH)(2)], the central ion is coordinated through the sulfur, and for the complexes [CdCl(2)(3TTSCH)], [CdBr(2)(3TTSCH)] the ion is coordinated through the sulfur as well as azomethine nitrogen atom of the thiosemicarbazone. In addition, fungistatic and bacteriostatic activities of both ligand and complexes have been evaluated. Cadmium(II) complexes have shown the most significant activities. PMID:20056280

Alomar, Kusaï; Landreau, Anne; Kempf, Marie; Khan, Mustayeen A; Allain, Magali; Bouet, Gilles

2010-04-01

135

Trace determination of low-molecular-mass substituted benzaldehydes in treated water using micro solid-phase extraction followed by liquid chromatography-mass spectrometric detection.  

PubMed

Aldehydes are a class of water disinfection by-products (DBPs) that are an object of special attention due to their high toxicity and carcinogenic effect. While aliphatic low-molecular-mass aldehydes (LMMAs) are often measured in waters, there is little information on the occurrence of aromatic LMMAs. This paper reports the development of a simple, rapid and sensitive method for the quantitative determination of six LMM substituted benzaldehydes (BAs) as DBPs in treated water. The method is based on the continuous in situ derivatisation/extraction of aldehydes on a Telos™ ENV ?-solid-phase extraction (?-SPE) column impregnated with 2,4-dinitrophenylhydrazine (DNPH). After elution of the hydrazones with acetonitrile (ACN), the derivatives are analysed using liquid chromatography-mass spectrometry (LC-MS). Under optimum conditions, limits of detection (LODs) were obtained between 15 and 25ng/L and the inter-day precision expressed as the relative standard deviation (RSD) ranged from 6.1% to 7.7%. Matrix effects were shown to be negligible by comparing the response factors (RFs) obtained in ultra-pure and treated waters. The proposed method is the first contribution developed for the analysis of LMM substituted BAs as DBPs in waters by LC-MS. Some of the aromatic LMMAs identified had not previously been reported for swimming pool water. PMID:23768532

Fernández-Molina, José María; Silva, Manuel

2013-07-26

136

Colorimetric recognition of acetate anions in aqueous solution using charge neutral azo derivatives  

NASA Astrophysics Data System (ADS)

Two novel highly sensitive colorimetric acetate anion receptors: 4-phenylazo-2-hydroxy-benzaldehyde 4-nitrophenylhydrazone ( 1) and 4-phenylazo-2-hydroxy-benzaldehyde 2,4-dinitrophenylhydrazone ( 2) based on azo derivative have been designed and synthesized. UV-vis experiments show that receptor 1 and receptor 2 can selectively recognize acetate in DMSO and even in 9/1 DMSO/H 2O (v/v) mixtures. Meanwhile the color changes induced by anions can provide a way of detection by 'naked-eye'. The further insights to the nature of interactions between receptor 1, 2 and AcO - have been investigated by 1H NMR titration experiments.

Huang, Weiwei; Li, Yaping; Lin, Hai; Lin, Huakuan

2012-02-01

137

Synthesis, characterization, and antibacterial activity of novel Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) complexes with vitamin K3-thiosemicarbazone.  

PubMed

Vitamin K3-thiosemicarbazone (C12H11N3NaO4S2 x 5H2O, abbreviated as VT), a new Schiff base derivative, has been synthesized. Its crystal structure, determined by X-ray diffraction, is triclinic, space group P1. We have also prepared five novel complexes of VT with transition metals: [M(VT)(2)2H2O] x nH2O, (n = 1 and 2 for M = Cu(II) and Zn(II), respectively) and [M'(HVT)2Cl2] x mH2O, (m = 4, 5, and 7 for M' = Co(II), Mn(II), and Ni(II), respectively). These compounds were characterized by IR and UV-Vis spectroscopy, molar conductivity, thermal analyses, complexometric titration, and elemental analysis. In all the complexes, the VT ligand coordinates through sulfur and oxygen atoms, and the geometry around metal atom is best described as octahedral. In vitro tests of antibacterial activity showed that VT and its complexes with Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) all had strong inhibitory actions against G(+) Staphylococcus aureus, G(+) Hay bacillus, and G(-) Escherichia coli. PMID:10766340

Li, Q X; Tang, H A; Li, Y Z; Wang, M; Wang, L F; Xia, C G

2000-01-30

138

Design, synthesis, and characterization of novel iron chelators: structure-activity relationships of the 2-benzoylpyridine thiosemicarbazone series and their 3-nitrobenzoyl analogues as potent antitumor agents.  

PubMed

Previously, we demonstrated that the potent antiproliferative activity of the di-2-pyridylketone thiosemicarbazone (DpT) series of Fe chelators was due to their ability to induce Fe depletion and form redox-active Fe complexes (Richardson, D. R.; et al. J. Med. Chem. 2006, 49, 6510-6521). We now examine the role of aromatic substituents on the antiproliferative and redox activity of novel DpT analogues, namely, the 2-benzoylpyridine thiosemicarbazone (BpT) and 2-(3-nitrobenzoyl)pyridine thiosemicarbazone (NBpT) series. Both series exhibited selective antiproliferative effects, with the majority having greater antineoplastic activity than their DpT homologues. This makes the BpT chelators the most active anticancer agents developed within our laboratory. The BpT series Fe complexes exhibit lower redox potentials than their corresponding DpT and NBpT complexes, highlighting their enhanced redox activity. The increased ability of BpT-Fe complexes to catalyze ascorbate oxidation and benzoate hydroxylation, relative to their DpT and NBpT analogues, suggested that redox cycling plays an important role in their antiproliferative activity. PMID:17602603

Kalinowski, Danuta S; Yu, Yu; Sharpe, Philip C; Islam, Mohammad; Liao, Yi-Tyng; Lovejoy, David B; Kumar, Naresh; Bernhardt, Paul V; Richardson, Des R

2007-07-26

139

Flow injection analysis of mercury using 4-(dimethylamino) benzaldehyde-4-ethylthiosemicarbazone as the ionophore of a coated wire electrode.  

PubMed

A flow injection analysis (FIA) incorporating a thiosemicarbazone-based coated wire electrode (CWE) was developed method for the determination of mercury(II). A 0.1 M KNO(3) carrier stream with pH between 1 and 5 and flow rate of 1 mL·min(-1) were used as optimum parameters. A linear plot within the concentration range of 5 × 10(-6)–0.1 M Hg(II), slope of 27.8 ± 1 mV per decade and correlation coefficient (R2) of 0.984 were obtained. The system was successfully applied for the determination of mercury(II) in dental amalgam solutions and spiked environmental water samples. Highly reproducible measurements with relative standard deviation (RSD < 1% (n = 3)) were obtained, giving a typical throughput of 30 samples·h(-1). PMID:23202196

Tahir, Tara F; Salhin, Abdussalam; Ab Ghani, Sulaiman

2012-01-01

140

Flow Injection Analysis of Mercury Using 4-(Dimethylamino) Benzaldehyde-4-Ethylthiosemicarbazone as the Ionophore of a Coated Wire Electrode  

PubMed Central

A flow injection analysis (FIA) incorporating a thiosemicarbazone-based coated wire electrode (CWE) was developed method for the determination of mercury(II). A 0.1 M KNO3 carrier stream with pH between 1 and 5 and flow rate of 1 mL·min?1 were used as optimum parameters. A linear plot within the concentration range of 5 × 10?6–0.1 M Hg(II), slope of 27.8 ± 1 mV per decade and correlation coefficient (R2) of 0.984 were obtained. The system was successfully applied for the determination of mercury(II) in dental amalgam solutions and spiked environmental water samples. Highly reproducible measurements with relative standard deviation (RSD < 1% (n = 3)) were obtained, giving a typical throughput of 30 samples·h?1.

Tahir, Tara F.; Salhin, Abdussalam; Ghani, Sulaiman Ab

2012-01-01

141

Polymer characterization and optimization of conditions for the enhanced bioproduction of benzaldehyde by Pichia pastoris in a two-phase partitioning bioreactor.  

PubMed

Benzaldehyde, with its apricot and almond-like aroma, is the second most abundantly used molecule in the flavor industry, and is most commonly produced via chemical routes, such as by the oxidation of toluene. Biologically produced benzaldehyde, whether by extraction of plant material or via microbial biotransformation, commands a substantial price advantage, and greater consumer acceptance. Methylotrophic yeast, such as Pichia pastoris, contain the enzyme alcohol oxidase (AOX), which, in the presence of alcohols other than methanol, are able to yield aldehydes as dead-end products, for example, benzaldehyde from benzyl alcohol. In this work, we have determined that benzaldehyde, and not benzyl alcohol, is inhibitory to the transformation reaction by P. pastoris, prompting the development of a selection strategy for identifying sequestering polymers for use in a partitioning bioreactor that was based on the ratio of partition coefficients (PCs) for the two target molecules. Additionally, we have now confirmed for the first time, that the mechanism of solute uptake by amorphous polymers is via absorption, not adsorption. Finally, we have adopted a common strategy used for the production of heterologous proteins by P. pastoris, namely the use of a mixed methanol/glycerol feed for inducing the required AOX enzyme, while reducing the time required for high density biomass generation. All of these components were combined in a final experiment in which 10% of the polymer Kraton D1102K, whose PC ratio of benzaldehyde to benzyl alcohol was 14.9, was used to detoxify the biotransformation in a 5 L partitioning bioreactor, resulting in a 3.4-fold increase in benzaldehyde produced (14.4 g vs. 4.2 g) relative to single phase operation, at more than double the volumetric productivity (97 mg L(-1) h(-1) vs. 41 mg L(-1) h(-1) ). PMID:23124524

Craig, Tom; Daugulis, Andrew J

2013-04-01

142

Tunable synthesis of 3-acyl-2-naphthols and 3-substituted isocoumarins via Jones reagent promoted cascade reactions of 2-(4-hydroxy-but-1-ynyl)benzaldehydes.  

PubMed

Novel and efficient synthesis of 3-acyl-2-naphthols and 3-substituted isocoumarins via the tunable cascade reactions of 2-(4-hydroxy-but-1-ynyl)benzaldehydes have been developed. Treatment of 2-(4-hydroxy-but-1-ynyl)benzaldehydes with 0.7 equiv of Jones reagent in CH3CN and subsequent purification through column chromatography on silica gel pre-eluted with Et3N afforded 3-acyl-2-naphthols with high efficiency. When the same substrates were treated with 3 equiv of Jones reagents in acetone, on the other hand, 3-substituted isocoumarins could be obtained in good yields. PMID:24028198

He, Yan; Zhang, Xinying; Shen, Nana; Fan, Xuesen

2013-10-18

143

Growth, spectral, optical, thermal, crystallization perfection and nonlinear optical studies of novel nonlinear optical crystal—Urea thiosemicarbazone monohydrate  

NASA Astrophysics Data System (ADS)

Single crystals of organic nonlinear material urea thiosemicarbazone monohydrate (UTM) have been grown by slow evaporation method. The grown crystals were characterized by single crystal X-ray diffraction analysis reveals that sample crystallized in triclinic system with noncentrosymmetric space group P1. Powder XRD pattern confirmed that grown crystal posses highly crystalline nature. FTIR spectrum was recorded to identify the presence of functional groups and molecular structure was confirmed by 1H NMR spectrum. Material confirmation of title compound has been performed by using mass spectroscopic analysis. Elemental composition of grown crystal was confirmed by energy-dispersive spectrometry (EDS). To study the crystalline perfection of the grown crystals, high-resolution X-ray diffraction (HR-XRD) study was carried out. Thermogravimetric and differential thermal analyses were employed to understand the thermal and physio-chemical stability of the synthesized compound. UV-Vis-NIR spectrum revealed the transmission properties of the crystal specimen. Relative SHG efficiency is measured by Kurtz and Perry method and found to about 0.89 times that of standard potassium dihydrogen phosphate (KDP) crystals.

Hanumantharao, Redrothu; Kalainathan, S.; Bhagavannarayana, G.

2012-06-01

144

Synthesis, spectroscopic, anticancer and antibacterial studies of Ni(II) and Cu(II) complexes with 2-carboxybenzaldehyde thiosemicarbazone.  

PubMed

Ni(II) and Cu(II) complexes of 2-carboxybenzaldehyde thiosemicarbazone (L) were synthesized and investigated by their spectral and analytical data. These newly synthesized complexes have a composition of M(L)X(H2O)2 (where M=Ni(II), Cu(II) and X=Cl(-), NO3(-), CH3COO(-)) and (L) is the tridentate Schiff base ligand. The ligand and its complexes have been characterized on the basis of analytical, molar conductivity, magnetic susceptibility measurements, FT-IR, ESR, (1)H NMR and electronic spectral analysis. All the compounds were non-electrolytic in nature. On the basis of spectral studies an octahedral geometry has been assigned for Ni(II) and a tetragonal geometry for Cu(II) complexes. The ligand and its metal complexes were screened for their anticancer studies against human breast cancer cell lines MCF-7 and calculated minimum inhibitory concentration and also for antibacterial activity using Kirby-Bauer single disk susceptibility test. PMID:24747857

Chandra, Sulekh; Vandana

2014-08-14

145

Synthesis, spectroscopic, anticancer and antibacterial studies of Ni(II) and Cu(II) complexes with 2-carboxybenzaldehyde thiosemicarbazone  

NASA Astrophysics Data System (ADS)

Ni(II) and Cu(II) complexes of 2-carboxybenzaldehyde thiosemicarbazone (L) were synthesized and investigated by their spectral and analytical data. These newly synthesized complexes have a composition of M(L)X(H2O)2 (where M = Ni(II), Cu(II) and X = Cl-, NO3-, CH3COO-) and (L) is the tridentate Schiff base ligand. The ligand and its complexes have been characterized on the basis of analytical, molar conductivity, magnetic susceptibility measurements, FT-IR, ESR, 1H NMR and electronic spectral analysis. All the compounds were non-electrolytic in nature. On the basis of spectral studies an octahedral geometry has been assigned for Ni(II) and a tetragonal geometry for Cu(II) complexes. The ligand and its metal complexes were screened for their anticancer studies against human breast cancer cell lines MCF-7 and calculated minimum inhibitory concentration and also for antibacterial activity using Kirby-Bauer single disk susceptibility test.

Chandra, Sulekh; Vandana

2014-08-01

146

Fluorescent gallium and indium bis(thiosemicarbazonates) and their radiolabelled analogues: synthesis, structures and cellular confocal fluorescence imaging investigations.  

PubMed

New fluorescent and biocompatible aromatic Ga(III)- and In(III)-bis(thiosemicarbazonato) complexes for dual mode optical and PET or SPECT molecular imaging have been synthesised via a synthetic method based on transmetallation reactions from Zn(II) precursors. Complexes have been fully characterised in the solid state by single crystal X-ray diffraction and in solution by spectroscopic methods (UV/Vis, fluorescence, (1)H and (13)C{(1)H} NMR). The bis(thiosemicarbazones) radiolabelled rapidly in high yields under mild conditions with (111)In (a gamma and Auger emitter for SPECT imaging and radiotherapy with t(1/2) = 2.8 d) and (68)Ga (a generator-available positron emitter for PET imaging with t(1/2) = 68 min). Cytotoxicity and biolocalisation studies using confocal fluorescence imaging and fluorescence lifetime imaging (FLIM) techniques have been used to study their in vitro activities and stabilities in HeLa and PC-3 cells to ascertain their suitability as synthetic scaffolds for future multimodality molecular imaging in cancer diagnosis and therapy. The observation that the indium complexes show certain nuclear uptake could be of relevance towards developing (111)In therapeutic agents based on Auger electron emission to induce DNA damage. PMID:21594287

Arrowsmith, Rory L; Waghorn, Philip A; Jones, Michael W; Bauman, Andreas; Brayshaw, Simon K; Hu, Zhiyuan; Kociok-Köhn, Gabriele; Mindt, Thomas L; Tyrrell, Rex M; Botchway, Stanley W; Dilworth, Jonathan R; Pascu, Sofia I

2011-06-21

147

Metal-catalysed oxidation processes in thiosemicarbazones: new complexes with the ligand N-{2-([4-N-ethylthiosemicarbazone]methyl)phenyl}-p-toluenesulfonamide.  

PubMed

The coordination behaviour of a new thiosemicarbazone Schiff-base building block, N-{2-([4-N-ethylthiosemicarbazone]methyl)phenyl}-p-toluenesulfonamide, H2L1 (1), incorporating a bulky tosyl group, towards Mn II, Fe II, Co II, Ni II, Cu II, Zn II, Cd II, Ag I, Sn II, and Pb II has been investigated by means of an electrochemical preparative procedure. Most metal complexes of L1 have the general formula [M(L1)]2.nX (M=Mn, Fe, Co, Ni, Cu, Cd, Pb; n=0-4, X=H2O or CH3CN), as confirmed by the structure of [Pb(L1)]2 (15), in which the lone pair on lead is stereochemically active. This lead(II) complex shows an intense fluorescence emission with a quantum yield of 0.13. In the case of silver, the complex formed was found to possess a stoichiometry of [Ag2(L1)]2.3H2O. During reactions with manganese and copper metals, interesting catalysed processes have been found to take place, with remarkable consequences regarding the ligand skeleton structure. In synthesising the manganese complex, we obtained an unexpected dithiolate thiosemicarbazone tosyl ligand, H2L2, as a side-product, which has been fully characterised, including by X-ray diffraction analysis. In the case of copper, the solid complex has the formula [CuL1]2, but the crystallised product shows the copper atoms coordinated to a new cyclised thiosemicarbazone ligand, H2L3, as in the structures of the complexes [Cu(L3)]2.CH3CN (8) and [Cu(L3)(H2O)]2.CH3CN.H2O (9). The zinc complex [Zn(L1)]4 (12) displays a particular tetranuclear zeolite-type structure capable of hosting small molecules or ions, presumably through hydrogen bonding. PMID:17918755

Pedrido, Rosa; Romero, María J; Bermejo, Manuel R; González-Noya, Ana M; García-Lema, Iria; Zaragoza, Guillermo

2008-01-01

148

Spectroscopic and biological approach of Ni(II), Cu(II) and Co(II) complexes of 4-methoxy/ethoxybenzaldehyde thiosemicarbazone glyoxime.  

PubMed

Two novel vicinal dioxime ligands containing (4-methoxybenzaldehyde thiosemicarbazone glyoxime (L(1)H2) or 4-ethoxybenzaldehyde thiosemicarbazone glyoxime (L(2)H2)) thiosemicarbazone units were synthesized and characterized using (1)H NMR, (13)C NMR, HMQC, MS, infrared and, UV-VIS. spectroscopy, elemental analysis, and magnetic susceptibility measurements. Mononuclear nickel(II), copper(II) and cobalt(II) complexes with a metal:ligand ratio of 1:2 for L(1)H2 and L(2)H2 were also synthesized. The effect of pH and solvent on the absorption spectra of both ligands and complexes was determined. IR spectra show that the ligands act in a bidentate manner and coordinates N4 donor groups of the ligands to Ni(II), Cu(II) and Co(II) ions. The detection of H-bonding (O-H?O) in the [M(LH)2] metal complexes by IR spectra supported the square-planar MN4 coordination of mononuclear complexes. The antimicrobial activities of compounds L(1)H2, L(2)H2, and their Ni(II), Cu(II) and Co(II) complexes were evaluated using the disc diffusion method against 12 bacteria and 4 yeasts. The minimal inhibitory concentrations (MICs) against 7 bacteria and 3 yeasts were also determined. Among the test compounds attempted, L(1)H2, [Ni(L1H)2], [Cu(L1H)2], L2H2, [Ni(L2H)2] and [Cu(L2H)2] showed some activities against certain Gram-positive bacteria and some of the yeasts tested. PMID:24239764

Babahan, Ilknur; Eyduran, Fatih; Coban, Esin Poyrazoglu; Orhan, Nil; Kazar, Didem; Biyik, Halil

2014-03-01

149

Toxicology and Carcinogenesis Studies of Benzaldehyde (Cas No. 100-52-7) in F344/N Rats and B6C3F1 Mice (Gavage Studies).  

National Technical Information Service (NTIS)

Two-year toxicology and carcinogenesis studies were conducted by administering 0, 200, or 400 mg/kg benzaldehyde in corn oil by gavage, 5 days per week for 103 weeks to groups of 50 male and 50 female rats and for 104 weeks to groups of 50 male mice. Grou...

J. Bishop

1990-01-01

150

Indenoindolone derivatives as topoisomerase II-inhibiting anticancer agents.  

PubMed

Based on known heterocyclic topoisomerase II inhibitors and anticancer agents, various indenoindolone derivatives were predicted as potential topoisomerase II-inhibiting anticancer agents. They are hydrazones, (thio)semicarbazones, and oximes of indenoindolones, and indenoindolols. These derivatives with suitable substitutions exhibited potent specific inhibition of human DNA TopoII? while not showing inhibition of topoisomerase I and DNA intercalation, despite the fact that parent indenoindolones are known poor/moderate inhibitors of topoisomerase II. The potent topoisomerase II inhibitor indenoindolone derivatives exhibited good anticancer activities compared to etoposide and 5-fluorouracil, and relatively low toxicity to normal cells. These derivatizations of indenoindolones were found to result in enhancement of anticancer activities. PMID:23321564

Kashyap, Maneesh; Kandekar, Somnath; Baviskar, Ashish T; Das, Dipon; Preet, Ranjan; Mohapatra, Purusottam; Satapathy, Shakti Ranjan; Siddharth, Sumit; Guchhait, Sankar K; Kundu, Chanakya N; Banerjee, Uttam C

2013-02-15

151

Enhanced sensitivity of self-assembled-monolayer-based SPR immunosensor for detection of benzaldehyde using a single-step multi-sandwich immunoassay.  

PubMed

This paper describes the fabrication and sensing characteristics of a self-assembled monolayer (SAM)-based surface plasmon resonance (SPR) immunosensor for detection of benzaldehyde (BZ). The functional sensing surface was fabricated by the immobilization of a benzaldehyde-ovalbumin conjugate (BZ-OVA) on Au-thiolate SAMs containing carboxyl end groups. Covalent binding of BZ-OVA on SAM was found to be dependent on the composition of the base SAM, and it is improved very much with the use of a mixed monolayer strategy. Based on SPR angle measurements, the functional sensor surface is established as a compact monolayer of BZ-OVA bound on the mixed SAM. The BZ-OVA-bound sensor surface undergoes immunoaffinity binding with anti-benzaldehyde antibody (BZ-Ab) selectively. An indirect inhibition immunoassay principle has been applied, in which analyte benzaldehyde solution was incubated with an optimal concentration of BZ-Ab for 5 min and injected over the sensor chip. Analyte benzaldehyde undergoes immunoreaction with BZ-Ab and makes it inactive for binding to BZ-OVA on the sensor chip. As a result, the SPR angle response decreases with an increase in the concentration of benzaldehyde. The fabricated immunosensor demonstrates a low detection limit (LDL) of 50 ppt (pg mL(-1)) with a response time of 5 min. Antibodies bound to the sensor chip during an immunoassay could be detached by a brief exposure to acidic pepsin. With this surface regeneration, reusability of the same sensor chip for as many as 30 determination cycles has been established. Sensitivity has been enhanced further with the application of an additional single-step multi-sandwich immunoassay step, in which the BZ-Ab bound to the sensor chip was treated with a mixture of biotin-labeled secondary antibody, streptavidin and biotin-bovine serum albumin (Bio-BSA) conjugate. With this approach, the SPR sensor signal increased by ca. 12 times and the low detection limit improved to 5 ppt with a total response time of no more than ca. 10 min. Figure A single-step multi-sandwich immunoassay step increases SPR sensor signal by ca. 12 times affording a low detection limit for benzaldehyde of 5 ppt. PMID:17318518

Gobi, K Vengatajalabathy; Matsumoto, Kiyoshi; Toko, Kiyoshi; Ikezaki, Hidekazu; Miura, Norio

2007-04-01

152

Antioxidant and antitumor activities of new synthesized aromatic C-nucleoside derivatives.  

PubMed

The carbohydrazide 1 was used as the precursor for the synthesis of a number of new aromatic C-nucleosides containing 1,3,4-oxadiazole 7, [1,3,4]oxadiazolo[2,3-a]isoindole 10b and pyrazole units 18. On the other hand, the thiosemicarbazone 20 was used as the key intermediate for synthesis of 1,3,4-oxadiazole  and 1,2,4-triazole-3-thione derivatives 21 and 23. The antioxidant activities of the prepared compounds were evaluated. The carbohydrazide 1 in particular was found to have potent antioxidant and antitumor activity. PMID:24759075

El Sadek, Mohamed M; Abd El-Dayem, Nagwa S; Hassan, Seham Y; Mostafa, Mohamed A; Yacout, Galila A

2014-01-01

153

A diastereoselective approach to enantiopure 3-substituted pyrrolidines from masked lithium homoenolates derived from norephedrine  

Microsoft Academic Search

N-alkoxycarbonyl-2-(2?-bromoethyl)oxazolidines derived from norephedrines are transformed into lithium derivatives by reaction with 1 or 2 equiv of tert-butyllithium in Et2O. The lithium intermediates readily cyclize to bicyclic lactams that react with acetaldehyde and benzaldehyde leading to the addition products in excellent chemical yields and moderate diastereoselectivities. Removal of the chiral appendage provides enantiopure 3-substituted pyrrolidines.

S. García-Granda; A. Gutiérrez-Rodríguez

1996-01-01

154

Growth and characterization of organic non-linear optical crystal 4-hydoroxy benzaldehyde-N-methyl 4-stilbazolium tosylate (HBST).  

PubMed

The 4-hydroxy benzaldehyde-N-methyl 4-stilbazolium tosylate (HBST), a good non-linear optical (NLO) crystal has been synthesized and the single crystal has been grown by slow evaporation method. In this work we have used ethyl acetate mixed methanol (1:1 ratio) as solvent. The lattice parameters were calculated from the powder X-ray diffraction patterns and compared with previous reports. The crystalline perfection has been verified with multicrystal X-ray diffractometer. The functional groups were identified from FTIR and NMR spectral studies. In order to know the optical quality of the grown crystal, the UV-Vis-NIR absorption spectrum was recorded and optical transition energy levels were also calculated. The thermal properties were analyzed from TG/DTA data. The relative SHG efficiency was compared with urea by Kurtz powder method. PMID:19251477

Jagannathan, K; Kalainathan, S; Bhagavannarayana, G

2009-07-01

155

Thermal, optical, mechanical and dielectric properties of nonlinear optical crystal 4-methoxy benzaldehyde-N-methyl 4-stilbazolium tosylate  

NASA Astrophysics Data System (ADS)

We have grown organic nonlinear optical 4-methoxy benzaldehyde-N-methyl-4-stilbazolium tosylate (MBST) crystals by slow evaporation technique. The grown crystals were analyzed by powder XRD, FTIR, NMR, UV, Thermal, mechanical and dielectric measurements. Lattice parameters and crystallinity of the crystal is confirmed by the XRD studies. The FTIR and NMR studies give the details about the various functional groups present. In order to study the optical quality of the crystal, the UV-vis absorption spectrum was recorded and cut-off wavelength was determined. Melting point of the crystal is found from the differential scanning calorimetry. The powder SHG studies were done with the Kurtz powder technique and the NLO efficiency is 17.2 times greater than that of urea. The surface of the grown crystal was analyzed with etching. Laser damage threshold studies have been carried out for the crystal using a Q-switched Nd:YAG laser of 10 ns pulses.

Sher Gill, Amirdha; Kalainathan, S.

2011-09-01

156

Rotational Spectrum and Large Amplitude Motions of 3,4-, 2,5- and 3,5-DIMETHYL-BENZALDEHYDE  

NASA Astrophysics Data System (ADS)

The microwave spectra of the 3,4-, 2,5- and 3,5-Dimethyl-Benzaldehyde (DMBA) molecules have been recorded for the first time in the 2-26.5 GHz frequency range, using the COBRA-FTMW spectrometer in Hannover, with an instrumental uncertainty of 0.5 kHz for unblended lines. The experimental assignments and fits are supplemented by ab initio quantum chemical calculations,conformational energy landscape, and dipole moment components. The analysis of the spectra for the three isomers are in progress. The latest results, including spectroscopic constants and large amplitude motion parameters, will be presented. This investigation follows the study of the spectra of the 4-Methyl-Benzaldehyde molecule. The DMBA isomers belong to a similar series of molecules formally obtained by adding a second methyl group at the aromatic ring. These molecules serve as prototype systems for the development of the theoretical model of asymmetric top molecules having Cs symmetry while containing two inequivalent methyl tops (C3v), exhibiting different barrier heights and coupling terms to methyl internal rotation. Thus, the DMBA isomers represent benchmark species for testing the two-top internal rotors BELGI program written recently. Supported by the ANR-08-BLAN-0054 contract (France), the Deutsche Forschungsgemeinschaft, and the Land Niedersachsen (Germany). H. Saal, W. Caminati, I. Kleiner, A. R. Hight-Walker, J. T. Hougen, J.-U. Grabow, to be published. M. Tudorie, I. Kleiner, J. T. Hougen, S. Melandri, L. W. Sutikdja, W. Stahl, J. Mol. Spectrosc., 269 (2011), 211-225

Kleiner, I.; Tudorie, M.; Jahn, M.; Grabow, J.-U.; Goubet, M.

2012-06-01

157

RuO 4 -mediated oxidation of N -benzylated tertiary amines. 3. Behavior of 1,4-dibenzylpiperazine and its oxygenated derivatives  

Microsoft Academic Search

1,4-Dibenzylpiperazine (1),-2-piperazinone (7),-2,6-piperazinedione (9), and 1-benzoyl-4-benzylpiperazine (30) were oxidized\\u000a by RuO4 (generated in situ) by attack at their endocyclic and exocyclic (i.e., benzylic) aminic N-?-C-H bonds to afford various oxygenated derivatives, including acyclic diformamides, benzaldehyde, and benzoic acid. The\\u000a reaction outcome was complicated by (i) the hydrolysis of diformamides, occurred during the work-up, and (ii) the reaction\\u000a of benzaldehyde with

Horia Petride; Constantin Dr?ghici; Cristina Florea; Aurica Petride

2006-01-01

158

Redox activation of Fe(III)-thiosemicarbazones and Fe(III)-bleomycin by thioredoxin reductase: specificity of enzymatic redox centers and analysis of reactive species formation by ESR spin trapping  

PubMed Central

Thiosemicarbazones such as triapine (Tp) and Dp44mT are tridentate iron (Fe) chelators that have well-documented anti-neoplastic activity. While Fe-thiosemicarbazones can undergo redox-cycling to generate reactive species that may have important roles in their cytotoxicity, there is only limited insight into specific cellular agents that can rapidly reduce Fe(III)-thiosemicarbazones and thereby promote their redox activity. Here we report that thioredoxin reductase-1 (TrxR1) and glutathione reductase (GR) have this activity, and that there is considerable specificity to the interactions between specific redox centers in these enzymes and different Fe(III) complexes. Site-directed variants of TrxR1 demonstrate that the selenocysteine (Sec) of the enzyme is not required, whereas the C59 residue and the flavin have important roles. While TrxR1 and GR have analogous C59/flavin motifs, TrxR is considerably faster than GR. For both enzymes, Fe(III)(Tp)2 is reduced faster than Fe(III)(Dp44mT)2. This reduction promotes redox cycling and the generation of hydroxyl radical (HO•) in a peroxide-dependent manner, even with low ?M levels of Fe(Tp)2. TrxR also reduces Fe(III)-bleomycin and this activity is Sec-dependent. TrxR cannot reduce Fe(III)-EDTA at significant rates. Our findings are the first to demonstrate pro-oxidant reductive activation of Fe(III)-based antitumor thiosemicarbazones by interactions with specific enzyme species. The marked elevation of TrxR in many tumors could contribute to the selective tumor toxicity of these drugs by enhancing the redox activation of Fe(III)-thiosemicarbazones and the generation of reactive oxygen species such as HO•

Myers, Judith M.; Cheng, Qing; Antholine, William E.; Kalyanaraman, Balaraman; Filipovska, Aleksandra; Arner, ArnerElias S.J.; Myers, Charles R.

2013-01-01

159

Synthesis, X-ray crystal structure, DNA binding, antioxidant and cytotoxicity studies of Ni(ii) and Pd(ii) thiosemicarbazone complexes.  

PubMed

New complexes, [Ni(HL)(PPh(3))]Cl (1), [Pd(L)(PPh(3))](2), and [Pd(L)(AsPh(3))](3), were synthesized from the reactions of 4-chloro-5-methyl-salicylaldehyde thiosemicarbazone [H(2)L] with [NiCl(2)(PPh(3))(2)], [PdCl(2)(PPh(3))(2)] and [PdCl(2)(AsPh(3))(2)]. They were characterized by IR, electronic, (1)H-NMR spectral data. Further, the structures of the complexes have been determined by single crystal X-ray diffraction. While the thiosemicarbazone coordinated as binegative tridentate (ONS) in complexes 2 and 3, it is coordinated as mono negative tridentate (ONS) in 1. The interactions of the new complexes with calf thymus DNA was examined by absorption and emission spectra, and viscosity measurements. Moreover, the antioxidant properties of the new complexes have also been tested against DPPH radical in which complex 1 exhibited better activity than that of the other two complexes 2 and 3. The in vitro cytotoxicity of complexes 1-3 against A549 and HepG2 cell lines was assayed, and the new complexes exhibited higher cytotoxic activity with lower IC(50) values indicating their efficiency in killing the cancer cells even at very low concentrations. PMID:22101384

Ramachandran, Eswaran; Kalaivani, Palaniappan; Prabhakaran, Rathinasabapathi; Rath, Nigam P; Brinda, Selvaraj; Poornima, Paramasivan; Padma, Viswanatha Vijaya; Natarajan, Karuppannan

2012-02-01

160

Potent 5-nitrofuran derivatives inhibitors of Trypanosoma cruzi growth: Electrochemical, spectroscopic and biological studies  

NASA Astrophysics Data System (ADS)

Cyclic voltammetry and electron spin resonance techniques were used in the investigation of several potential antiprotozoal containing thiosemicarbazone and carbamate nitrofurans. In the electrochemical behaviour, a self-protonation process involving the nitro group was observed. The reactivity of the nitro anion radical for these derivatives with glutathione, a biological relevant thiol, was also studied in means of cyclic voltammetry. These studies demonstrated that glutathione could react with radical species from 5-nitrofuryl system. Furthermore, from the voltammetric results, some parameters of biological significance as E71 (indicative of the biological nitro anion radical formation), and K (thermodynamic indicator the of oxygen redox cycling) have been calculated. We also evaluated the stability of the nitro anion radical in terms of the dimerization constant ( kd). The nitrofuran-free radicals from cyclic voltammetry were characterized by electron spin resonance. A clear dependence between both the thiosemicarbazone or carbamate substructure and the length of the linker, furyl- or furylpropenyl-spacer, and the delocalization of the unpaired electron was observed. Through of biological assays we obtained important parameters that account for the selective anti-trypanosomal activity of these derivatives. The trypomastigote viability study showed that all derivatives are as active as in the epimastigote form of the parasite in a doses dependent manner.

Maria Aravena, C.; Claudio Olea, A.; Cerecetto, Hugo; González, Mercedes; Maya, Juan Diego; Rodríguez-Becerra, Jorge

2011-07-01

161

Metformin induces an intracellular reductive state that protects oesophageal squamous cell carcinoma cells against cisplatin but not copper-bis(thiosemicarbazones)  

PubMed Central

Background Oesophageal squamous cell carcinoma (OSCC) is a highly aggressive carcinoma with a poor survival rate. One of the most commonly used chemotherapeutic drugs, cisplatin, displays varied and often poor efficacy in vivo. Therefore, alternative, cost-effective and more efficacious treatments are required. Metformin has been previously shown to reduce proliferative rates in various carcinoma cell lines. We report for the first time, the effect of metformin on OSCC cell proliferation and show that it antagonises cisplatin-induced but not copper-bis(thiosemicarbazone)-induced cytotoxicity in OSCC cells. Methods Cell proliferation and stage of the cell cycle were quantified by trypan blue counts and flow cytometry, respectively. All cytotoxicity measurements were made using the tetrazolium based MTT assay. Metabolic alterations to cells were determined as follows: glycolysis via a lactate dehydrogenase assay, reducing equivalents by MTT reduction and reduced intracellular thiols by monobromobimane-thiol fluorescence, and glutathione depletion using buthionine sulfoximine. Inductively coupled plasma mass spectrometry was used to quantify cisplatin-DNA adduct formation. Results Metformin was found to reduce cell proliferation significantly in all OSCC cell lines, with an accumulation of cells in G0/G1 phase of the cell cycle. However, metformin significantly protected OSCC cells against cisplatin toxicity. Our results indicate that a major mechanism of metformin-induced cisplatin resistance results from a significant increase in glycolysis, intracellular NAD(P)H levels with a concomitant increase in reduced intracellular thiols, leading to decreased cisplatin-DNA adduct formation. The glutathione synthesis inhibitor buthionine sulfoximine significantly ablated the protective effect of metformin. We subsequently show that the copper-bis(thiosemicarbazones), Cu-ATSM and Cu-GTSM, which are trapped in cells under reducing conditions, cause significant OSCC cytotoxicity, both alone and in combination with metformin. Conclusions This is the first study showing that metformin can be used to decrease cell proliferation in OSCC cells. However, metformin protects against cisplatin cytotoxicity by inducing a reducing intracellular environment leading to lower cisplatin-DNA adduct formation. As such, we advise that caution be used when administering cisplatin to diabetic patients treated with metformin. Furthermore, we propose a novel combination therapy approach for OSCC that utilises metformin with metformin-compatible cytotoxic agents, such as the copper-bis(thiosemicarbazones), Cu-ATSM and Cu-GTSM.

2014-01-01

162

Suitable combination of promoter and micellar catalyst for kilo fold rate acceleration on benzaldehyde to benzoic acid conversion in aqueous media at room temperature: A kinetic approach  

NASA Astrophysics Data System (ADS)

The kinetics of oxidation of benzaldehyde by chromic acid in aqueous and aqueous surfactant (sodium dodecyl sulfate, SDS, alkyl phenyl polyethylene glycol, Triton X-100 and N-cetylpyridinium chloride, CPC) media have been investigated in the presence of promoter at 303 K. The pseudo-first-order rate constants (kobs) were determined from a logarithmic plot of absorbance as a function time. The rate constants were found to increase with introduction of heteroaromatic nitrogen base promoters such as Picolinic acid (PA), 2,2'-bipyridine (bipy) and 1,10-phenanthroline (phen). The product benzoic acid has been characterized by conventional melting point experiment, NMR, HRMS and FTIR spectral analysis. The mechanism of both unpromoted and promoted reaction path has been proposed for the reaction. In presence of the anionic surfactant SDS, cationic surfactant CPC and neutral surfactant TX-100 the reaction can undergo simultaneously in both aqueous and micellar phase with an enhanced rate of oxidation in the micellar phase. Both SDS and TX-100 produce normal micellar effect whereas CPC produce reverse micellar effect in the presence of benzaldehyde. The observed net enhancement of rate effects has been explained by considering the hydrophobic and electrostatic interaction between the surfactants and reactants. SDS and bipy combination is the suitable one for benzaldehyde oxidation.

Ghosh, Aniruddha; Saha, Rumpa; Ghosh, Sumanta K.; Mukherjee, Kakali; Saha, Bidyut

2013-05-01

163

Suitable combination of promoter and micellar catalyst for kilo fold rate acceleration on benzaldehyde to benzoic acid conversion in aqueous media at room temperature: a kinetic approach.  

PubMed

The kinetics of oxidation of benzaldehyde by chromic acid in aqueous and aqueous surfactant (sodium dodecyl sulfate, SDS, alkyl phenyl polyethylene glycol, Triton X-100 and N-cetylpyridinium chloride, CPC) media have been investigated in the presence of promoter at 303 K. The pseudo-first-order rate constants (kobs) were determined from a logarithmic plot of absorbance as a function time. The rate constants were found to increase with introduction of heteroaromatic nitrogen base promoters such as Picolinic acid (PA), 2,2'-bipyridine (bipy) and 1,10-phenanthroline (phen). The product benzoic acid has been characterized by conventional melting point experiment, NMR, HRMS and FTIR spectral analysis. The mechanism of both unpromoted and promoted reaction path has been proposed for the reaction. In presence of the anionic surfactant SDS, cationic surfactant CPC and neutral surfactant TX-100 the reaction can undergo simultaneously in both aqueous and micellar phase with an enhanced rate of oxidation in the micellar phase. Both SDS and TX-100 produce normal micellar effect whereas CPC produce reverse micellar effect in the presence of benzaldehyde. The observed net enhancement of rate effects has been explained by considering the hydrophobic and electrostatic interaction between the surfactants and reactants. SDS and bipy combination is the suitable one for benzaldehyde oxidation. PMID:23501718

Ghosh, Aniruddha; Saha, Rumpa; Ghosh, Sumanta K; Mukherjee, Kakali; Saha, Bidyut

2013-05-15

164

Synthesis, characterization and in vitro anti-neoplastic activity of gypsogenin derivatives.  

PubMed

Gypsogenin (L(1); 3-hydroxy-23-oxoolean-12-en-28-oic acid), a natural saponin, was isolated from the boiling water extract of Gypsophila arrostii roots. In addition, the derivatives gypsogenin thiosemicarbazone (L(2); 23-[(aminocarbonothioyl)hydrazono]-3-hydroxolean-12-en-28-oic acid) and gypsogenin thiosemicarbazone glyoxime (L(3)H2; (3?)-3-hydroxy-23-[({[(1Z,2E)-N-hydroxy-2-(hydroxyimino)ethanimidoyl]amino}carbonothioyl)hydrazono] olean-12-en-28-oic acid) as well as the Cu(II) and Co(II) complexes of L(3)H2 were prepared. The structures were established on NMR analysis ((1)H, (13)C NMR, HMBC, HMQC, and NOESY), FT-IR and completed by analysis of LC/MS. Furthermore, the antiproliferative effects of the Co(II) and Cu(II) complexes of the gypsogenin derivatives were assayed in human promyelocytic leukemia (HL 60) cells. These complexes were found to be potent anticancer agents with concentrations that inhibited 50% of proliferation (IpC50) between 5?M and 40?M. Cell death was distinguished by HO/PI double staining. The Co(II) complex of L(3)H2 has shown approximately %50 apoptotic effect at 10?M concentration. Paclitaxel has been used as positive control. PMID:24463219

Emirda?-Öztürk, Safiye; Babahan, ?lknur; Özmen, Ali

2014-04-01

165

Spectral studies and structure of a 2-hydroxyacetophenone 3-hexamethyleneiminyl thiosemicarbazonate(-2) copper(II) complex containing 1,10-phenanthroline  

NASA Astrophysics Data System (ADS)

The spectral studies and structure of a ternary complex of copper(II) with 2-hydroxyacetophenone 3-hexamethyliminylthiosemicarbazonate (L 2-) and 1,10-phenanthroline (phen) are reported. The thiosemicarbazone binds to the metal as a dianionic ONS-donor (L 2-) ligand, and forms a complex of the stoichiometry [CuLphen]. The copper(II) complex was characterized by IR and UV/Vis spectroscopies, as well as by solid state room-temperature magnetic susceptibility. Spin Hamiltonian and bonding parameters of the compound are calculated from the EPR spectra. Computer simulation of EPR spectrum in DMF at 77 K aided the calculation of magnetic and bonding parameters of the compound. The structure of the compound is solved by single crystal X-ray diffraction. The geometry around copper is distorted square pyramidal.

John, Rohith P.; Sreekanth, A.; Prathapachandra Kurup, Maliyeckal R.; Usman, Anwar; Ibrahim, Abdul Razak; Fun, Hoong-Kun

2003-04-01

166

Evaluation of DNA binding, antioxidant and cytotoxic activity of mononuclear Co(III) complexes of 2-oxo-1,2-dihydrobenzo[h]quinoline-3-carbaldehyde thiosemicarbazones.  

PubMed

Four new 2-oxo-1,2-dihydrobenzo[h]quinoline-3-carbaldehyde N-substituted thiosemicarbazone ligands (H(2)-LR, where R = H, Me, Et or Ph) and their corresponding new cobalt(III) complexes have been synthesized and characterized. The structures of the complexes 2 and 3 were determined by single crystal X-ray diffraction analysis. The interactions of the new complexes with DNA were investigated by absorption, emission and viscosity studies which indicated that the complexes bind to DNA via intercalation. Antioxidant studies of the new complexes showed that the significant antioxidant activity against DPPH radical. In addition, the in vitro cytotoxicity of complexes 1-4 against A549 cell line was assayed which showed higher cytotoxic activity with lower IC(50) values indicating their efficiency in killing the cancer cells even at very low concentrations. PMID:22397923

Ramachandran, Eswaran; Thomas, Sajesh P; Poornima, Paramasivan; Kalaivani, Palaniappan; Prabhakaran, Rathinasabapathi; Padma, Viswanadha Vijaya; Natarajan, Karuppannan

2012-04-01

167

One pot synthesis of structurally different mono and dimeric Ni(II) thiosemicarbazone complexes and N-arylation on a coordinated ligand: a comparative biological study.  

PubMed

One pot synthesis of three structurally different Ni(II) thiosemicarbazone complexes 1, 2 and 3 were obtained from the reaction between [NiCl(2)(PPh(3))(2)], 1,2-bis(diphenylphosphino)ethane, and [H(2)-(Sal-tsc)]. The obtained products were characterized by various spectral and analytical techniques. From the X-ray crystallographic analysis, an unexpected N-arylation on the coordinated salicylaldehydethiosemicarbazone was found in complex 2. The comparative biological evolutions such as DNA/protein binding, antioxidant, cytotoxicity (MTT, LDH, and NO) and cellular uptake studies have been examined for [Ni(Sal-tsc)(PPh(3))] (1) and [(Ni(Sal-tsc))(2)(?-dppe)] (3). When comparing the cytotoxicity of the complexes, 1 exhibited higher activity than 2 and 3 and by comparing with standard cis-platin, both of them were found to exhibit better activity under identical conditions. PMID:22729216

Prabhakaran, R; Kalaivani, P; Poornima, P; Dallemer, F; Paramaguru, G; Vijaya Padma, V; Renganathan, R; Huang, R; Natarajan, K

2012-08-21

168

Using heavy atom rare gas matrix to control the reactivity of 4-methoxybenzaldehyde: A comparison with benzaldehyde  

NASA Astrophysics Data System (ADS)

Different patterns of photochemical behavior were observed for 4-methoxybenzaldehyde (p-anisaldehyde) isolated in xenon and in argon matrices. Monomers of the compound isolated in solid Xe decarbonylate upon middle ultraviolet irradiation, yielding methoxybenzene (anisole), and CO. On the other hand, p-anisaldehyde isolated in an Ar matrix and subjected to identical irradiation, predominantly isomerizes to the closed-ring isomeric ketene (4-methoxycyclohexa-2,4-dien-1-ylidene) methanone. Experimental detection of a closed-ring ketene photoproduct, generated from an aromatic aldehyde, constitutes a rare observation. The difference between the patterns of photochemical transformations of p-anisaldehyde isolated in argon and xenon environments can be attributed to the external heavy-atom effect, where xenon enhances the rate of intersystem crossing from the singlet to the triplet manifold in which decarbonylation (via p-methoxybenzoyl radical) takes place. The parent compound, benzaldehyde, decarbonylates (to benzene + CO) when subjected to middle ultraviolet irradiation in both argon and xenon matrices. This demonstrates the role of the methoxy p-anisaldehyde substituent in activation of the reaction channel leading to the formation of the ketene photoproduct.

Ku?, Nihal; Sharma, Archna; Reva, Igor; Lapinski, Leszek; Fausto, Rui

2012-04-01

169

Using heavy atom rare gas matrix to control the reactivity of 4-methoxybenzaldehyde: A comparison with benzaldehyde  

SciTech Connect

Different patterns of photochemical behavior were observed for 4-methoxybenzaldehyde (p-anisaldehyde) isolated in xenon and in argon matrices. Monomers of the compound isolated in solid Xe decarbonylate upon middle ultraviolet irradiation, yielding methoxybenzene (anisole), and CO. On the other hand, p-anisaldehyde isolated in an Ar matrix and subjected to identical irradiation, predominantly isomerizes to the closed-ring isomeric ketene (4-methoxycyclohexa-2,4-dien-1-ylidene) methanone. Experimental detection of a closed-ring ketene photoproduct, generated from an aromatic aldehyde, constitutes a rare observation. The difference between the patterns of photochemical transformations of p-anisaldehyde isolated in argon and xenon environments can be attributed to the external heavy-atom effect, where xenon enhances the rate of intersystem crossing from the singlet to the triplet manifold in which decarbonylation (via p-methoxybenzoyl radical) takes place. The parent compound, benzaldehyde, decarbonylates (to benzene + CO) when subjected to middle ultraviolet irradiation in both argon and xenon matrices. This demonstrates the role of the methoxy p-anisaldehyde substituent in activation of the reaction channel leading to the formation of the ketene photoproduct.

Kus, Nihal [Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal); Department of Physics, Anadolu University, 26470 Eskisehir (Turkey); Sharma, Archna; Reva, Igor; Fausto, Rui [Department of Chemistry, University of Coimbra, 3004-535 Coimbra (Portugal); Lapinski, Leszek [Institute of Physics, Polish Academy of Sciences, Warsaw (Poland)

2012-04-14

170

Influence of terminal substitution on structural, DNA, protein binding, anticancer and antibacterial activities of palladium(II) complexes containing 3-methoxy salicylaldehyde-4(N) substituted thiosemicarbazones.  

PubMed

The variable chelating behavior of 3-methoxysalicylaldehyde-4(N)-substituted thiosemicarbazones was observed in equimolar reactions with [PdCl(2)(PPh(3))(2)]. The new complexes were characterized by various analytical, spectroscopic techniques (mass, (1)H-NMR, absorption, IR). All the new complexes were structurally characterized by single crystal X-ray diffraction. Crystallographic results showed that the ligands H(2)L(1) and H(2)L(4) are coordinated as binegative tridentate ONS donor ligands in the complexes 1 and 4 by forming six and five member rings. However, the ligands H(2)L(2) and H(2)L(3) bound to palladium in 2 and 3 as uninegative bidentate NS donors by forming a five member chelate ring. From this study, it was found that the substitution on terminal 4(N)-nitrogen may have an influence on the chelating ability of thiosemicarbazone. The presence of hydrogen bonding in 2 and 3 might be responsible for preventing the coordination of phenolic oxygen to the metal ion. The interaction of the complexes with calf-thymus DNA (CT-DNA) has been explored by absorption and emission titration methods. Based on the observations, an electrostatic binding mode of DNA has been proposed. The protein binding studies were monitored by quenching of tryptophan and tyrosine residues in the presence of complexes using Lysozyme as model protein. Antibacterial activity studies of the complexes have been screened against pathogenic bacteria such as Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia and Pseudomonas aeruginosa. MIC50 values of the complexes showed that they exhibited significant activity against the pathogens and among them, 3 exhibited higher activity. Further, anticancer activity of the complexes on the lung cancer cell line A549 has also been studied. PMID:22222360

Kalaivani, P; Prabhakaran, R; Ramachandran, E; Dallemer, F; Paramaguru, G; Renganathan, R; Poornima, P; Vijaya Padma, V; Natarajan, K

2012-02-28

171

A new approach for simultaneous determination of Co(II), Ni(II), Cu(II) and Pd(II) using 2-thiophenaldehyde-3-thiosemicarbazone as reagent by solid phase microextraction–high performance liquid chromatography  

Microsoft Academic Search

A new method is proposed herein for the sorption, separation and simultaneous determination of Co(II), Ni(II), Cu(II) and Pd(II) using 2-thiophenaldehyde-3-thiosemicarbazone (TPTS) as a reagent by solid phase microextraction–high performance liquid chromatography–UV detection. The method is based upon the sorption of metal complexes on polydimethylsiloxane (PDMS) fiber from aqueous solution followed by desorption in the desorption chamber of solid phase

Varinder Kaur; Jatinder Singh Aulakh; Ashok Kumar Malik

2007-01-01

172

Simultaneous determination of the novel thiosemicarbazone anti-cancer agent, Bp4eT, and its main phase I metabolites in plasma: application to a pilot pharmacokinetic study in rats.  

PubMed

Novel thiosemicarbazone metal chelators are extensively studied anti-cancer agents with marked and selective activity against a wide variety of cancer cells, as well as human tumor xenografts in mice. This study describes the first validated LC-MS/MS method for the simultaneous quantification of 2-benzoylpyridine 4-ethyl-3-thiosemicarbazone (Bp4eT) and its main metabolites (E/Z isomers of the semicarbazone structure, M1-E and M1-Z, and the amidrazone metabolite, M2) in plasma. Separation was achieved using a C18 column with ammonium formate/acetonitrile mixture as the mobile phase. Plasma samples were treated using solid-phase extraction on 96-well plates. This method was validated over the concentration range of 0.18-2.80 ?M for Bp4eT, 0.02-0.37 ?M for both M1-E and M1-Z, and 0.10-1.60 ?M for M2. This methodology was applied to the analysis of samples from in vivo experiments, allowing for the concentration-time profile to be simultaneously assessed for the parent drug and its metabolites. The current study addresses the lack of knowledge regarding the quantitative analysis of thiosemicarbazone anti-cancer drugs and their metabolites in plasma and provides the first pharmacokinetic data on a lead compound of this class. PMID:24254882

Stariat, Ján; Suprunová, Vlasta; Roh, Jaroslav; Šesták, Vít; Eisner, Tomáš; Filipský, Tomáš; Mlad?nka, P?emysl; Nobilis, Milan; Šim?nek, Tomáš; Klimeš, Ji?í; Kalinowski, Danuta S; Richardson, Des R; Kova?íková, Petra

2014-05-01

173

Synthesis and biological evaluation of formazan derivatives  

PubMed Central

The formazan derivatives (FM1–FM5) were synthesized by the reaction of benzaldehyde phenylhydrazone with substituted aromatic and hetero aromatic amines. The structures of the synthesized compounds were then elucidated using UV, IR, 1H NMR and mass spectral data. The synthesized derivatives were screened for anticonvulsant, antibacterial and antiviral activities. All the compounds showed remarkable antibacterial activity at 250 ?g/ml, but FM4 and FM3 did not show any inhibition on Staphylococcus aureus and Vibriocholera, respectively. All the compounds showed significant anticonvulsant effect at 100 mg/kg p.o. and the experimental data were statistically significant at P<0.001 level. But none of the compounds was effective against Japanese encephalitis virus.

Mariappan, Gurusamy; Korim, Rejaul; Joshi, Nand Madhwa; Alam, Faruk; Hazarika, Rajib; Kumar, Deepak; Uriah, Tiewlasubon

2010-01-01

174

Heat of Mixing and Solution of Hexane C6H14 + C7H6O Benzaldehyde (HMSD1111, LB3801_H)  

NASA Astrophysics Data System (ADS)

This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Heat of Mixing and Solution of Hexane C6H14 + C7H6O Benzaldehyde (HMSD1111, LB3801_H)' providing data from direct low-pressure calorimetric measurement of molar excess enthalpy at variable mole fraction and constant temperature.

Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

175

Density, Viscosity, Sound Speed, and Thermoacoustical Parameters of Benzaldehyde with Chlorobenzene or Nitrobenzene at 303.15 K, 308.15 K, and 313.15 K  

NASA Astrophysics Data System (ADS)

The values of the density, viscosity, and speed of sound for binary liquid mixtures of benzaldehyde with chlorobenzene or nitrobenzene have been measured over the entire range of composition at (303.15, 308.15, and 313.15) K. These values have been used to calculate the excess molar volume (), and excess free volume (). McAllister's three-body interaction model is used for correlating the kinematic viscosity of binary mixtures. The thermophysical properties (density, viscosity, and ultrasonic velocity) under study were fit to the Jouyban-Acree model.

Lavanya, T. G.; Saravanakumar, K.; Baskaran, R.; Kubendran, T. R.

2013-07-01

176

Heat of Mixing and Solution of Benzaldehyde C7H6O + C7H16 Heptane (HMSD1111, LB3802_H)  

NASA Astrophysics Data System (ADS)

This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Heat of Mixing and Solution of Benzaldehyde C7H6O + C7H16 Heptane (HMSD1111, LB3802_H)' providing data from direct low-pressure calorimetric measurement of molar excess enthalpy at variable mole fraction and constant temperature.

Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

177

Heat of Mixing and Solution of Cyclohexane C6H12 + C7H6O Benzaldehyde (HMSD1111, LB3803_H)  

NASA Astrophysics Data System (ADS)

This document is part of Subvolume B 'Binary Liquid Systems of Nonelectrolytes II' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Heat of Mixing and Solution of Cyclohexane C6H12 + C7H6O Benzaldehyde (HMSD1111, LB3803_H)' providing data from direct low-pressure calorimetric measurement of molar excess enthalpy at variable mole fraction and constant temperature.

Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

178

Proline and benzylpenicillin derivatives grafted into mesoporous MCM-41: Novel organic-inorganic hybrid catalysts for direct aldol reaction  

Microsoft Academic Search

New organic-inorganic hybrid catalysts were synthesized by covalent grafting of proline and benzylpenicillin derivatives into\\u000a mesoporous MCM-41. These catalysts were extensively characterized using FT-IR,13C CP MAS solid stateNMR, XRD and TEM techniques. These were used as catalysts for direct, asymmetric aldol reaction between\\u000a acetone and activated aromatic aldehydes. In the reaction of 4-nitro and 4-fluoro benzaldehyde, the aldol products were

Dwairath Dhar; Ian Beadham; Srinivasan Chandrasekaran

2003-01-01

179

Lithium derivatives from enantiomerically pure 2-(2?-haloethyl) dioxolanes: Formation and use as chiral propanal homoenolate synthons  

Microsoft Academic Search

Condensation of acetals of 3-chloro- and 3-bromopropanal with (?)-1,4-di-O-benzyl-L-threitol and (?)-cis-2,3-bornanediol leads to the corresponding 2-(2?-chloroethyl-)- and 2-(2?-bromoethyl)dioxolanes that were converted into the Li-derivatives by transhalometallation with t-butyllithium in excellent yields. These chiral propanal homoenolates react with benzaldehyde and acetophenone yielding carbinols in moderate chemical yields and low diastereomeric excesses.

María García-Valverde; Rafael Pedrosa; Martina Vicente

1995-01-01

180

Synthesis, Spectroscopic and Polarographic Studies of Dibutyltin(IV) Complexes of Schiff Bases Derived from 2Aminophenol  

Microsoft Academic Search

A series of dibutyltin(IV) complexes of Schiff bases derived from 2-minophenol and benzaldehyde (HL), anisaldehyde (HL), 2-furfural (HL), acetophenone (HL), benzylmethyl ketone (HL), benzil (HL), salicylaldehyde (H2L), 2-hydroxy-l-naphthaldehyde (H2L) and 2-hydroxy-acetophenone (H2L) have been synthesized by the reaction of dibutyltin(IV) oxide with the preformed Schiff bases in 1:l or 1:2 molar ratios in benzene with azeotropical removal of water. The

Mala Nath; Nidhee Chaudhary

1998-01-01

181

Synthesis, characterization and molecular sensing capability of fac-[Re(CO) 3(? 2-N,N-dpktsc)Cl] where dpktsc = di-2-pyridylketone thiosemicarbazone  

NASA Astrophysics Data System (ADS)

When di-2-pyridyl ketone thiosemicarbazone (dpktsc) was allowed to react with [Re(CO) 5Cl] in toluene under reflux, fac-[Re(CO) 3(? 2-N,N-dpktsc)Cl] was isolated in good yield. The identity of fac-[Re(CO) 3(? 2-N,N-dpktsc)Cl] was established from the results of its elemental analysis, spectroscopic, and electrochemical properties. The infrared spectra of fac-[Re(CO) 3(? 2-N,N-dpktsc)Cl] show the facial coordination of the carbonyl groups, and the pyridyl N,N-coordination of dpktsc. 1H NMR measurements on fac-[Re(CO) 3(? 2-N,N-dpktsc)Cl] in d6-dmso and d6-acetone confirmed the pyridyl N,N-coordination of dpktsc, and showed strong solvent dependence as manifested by the sensitivity of thioamide and ammine protons to their surroundings. The electronic absorption spectra of fac-[Re(CO) 3(? 2-N,N-dpktsc)Cl] in protophilic solvents (dmso and dmf) display two intra-ligand charge transfer (ILCT) transitions at 476 and 360 nm and in non-protophilic solvents a single ILCT transition at 346 nm in CH 3CN and 342 nm in CH 2Cl 2. Reversible interconversion between fac-[Re(CO) 3(? 2-N,N-dpktsc)Cl] and its conjugate base was established in protophilic solvents using a base to shift the equilibrium to the conjugate base and an acid to shift the equilibrium or conjugate base to the neutral form. Substrates in concentrations as low as 1 × 10 -10 M can be detected and determined using protophilic solutions of fac-[Re(CO) 3(? 2-N,N-dpktsc)Cl]. When MCl 2 (M = Zn, Cd or Hg) was allowed to interact with fac-[Re(CO) 3(? 2-N,N-dpktsc)Cl] in protophilic solvents, the intensity of the low energy ILCT band disappeared and a shift in the high energy ILCT electronic transition was observed that hints to the coordination of MCl 2 to fac-[Re(CO) 3(? 2-N,N-dpktsc)Cl]. Electrochemical measurements on fac-[Re(CO) 3(? 2-N,N-dpktsc)Cl] in dmf showed sequential irreversible redox processes in accord with the electrochemical reduction or oxidation of the thiosemicarbazone moiety.

Bakir, Mohammed; Brown, Ordel

2009-07-01

182

Structure-activity relationship study of phenylpyrazole derivatives as a novel class of anti-HIV agents.  

PubMed

The structure-activity relationship of phenylpyrazole derivative 1 was investigated for the development of novel anti-HIV agents. Initial efforts revealed that the diazenyl group can be replaced by an aminomethylene group. In addition, we synthesized various derivatives by the reductive amination of benzaldehydes with 5-aminopyrazoles and carried out parallel structural optimization on the benzyl group and the pyrazole ring. This optimization led to a six-fold more potent derivative 32j than the lead compound 1, and this derivative has a 3',4'-dichloro-(1,1'-biphenyl)-3-yl group. PMID:23845222

Mizuhara, Tsukasa; Kato, Takayuki; Hirai, Atsushi; Kurihara, Hideki; Shimada, Yasuhiro; Taniguchi, Masahiko; Maeta, Hideki; Togami, Hiroaki; Shimura, Kazuya; Matsuoka, Masao; Okazaki, Shiho; Takeuchi, Tomoki; Ohno, Hiroaki; Oishi, Shinya; Fujii, Nobutaka

2013-08-15

183

Synthesis and Evaluation of Some New Aza-B-homocholestane Derivatives as Anticancer Agents  

PubMed Central

Using analogues of some marine steroidal oximes as precursors, a series of aza-B-homocholestane derivatives possessing different substituted groups at the 3-position of the steroidal nucleus were synthesized. Their biological activity against cancer cell proliferation was determined with multiple cancer cell lines. Aza-B-homocholestane derivatives possessing 3-hydroxyl, 3-hydroximino and 3-thiosemicarbazone groups displayed remarkable cytotoxicity to cancer cells via apoptosis inducing mechanism. Compounds 5, 10, 12, 15 and 18 exhibited better potency to inhibit cancer cell proliferation. In addition, compound 15 was further evaluated with three dimensional (3D) multicellular spheroids assay to determine its potency against spheroid growth. The structure-activity relationship (SAR) generated in the studies is valuable for the design of novel chemotherapeutic agents.

Huang, Yanmin; Cui, Jianguo; Chen, Sijing; Lin, Qifu; Song, Huacan; Gan, Chunfang; Su, Bin; Zhou, Aimin

2014-01-01

184

A Copper Chelate of Thiosemicarbazone NSC 689534 induces Oxidative/ER Stress and Inhibits Tumor Growth In Vitro and In Vivo  

PubMed Central

In this study, a Cu2+ chelate of the novel thiosemicarbazone NSC 689534 was evaluated for in vitro and in vivo anti-cancer activity. Results demonstrated that NSC 689534 activity (low µM range) was enhanced 4–5 fold by copper chelation and completely attenuated by iron. Importantly, once formed, the NSC 689534/Cu2+ complex retained activity in the presence of additional iron or iron-containing biomolecules. NSC 689534/Cu2+ mediated its effects primarily through the induction of ROS, with depletion of cellular glutathione and protein thiols. Pre-treatment of cells with the antioxidant L-NAC impaired activity, whereas NSC 689534/Cu2+ effectively synergized with the glutathione biosynthesis inhibitor, buthionine sulphoximine. Microarray analysis of NSC 689534/Cu2+-treated cells highlighted activation of pathways involved in oxidative and ER-stress/UPR, autophagy and metal metabolism. Further scrutiny of the role of ER-stress and autophagy indicated that NSC 689534/Cu2+ -induced cell death was ER-stress dependent and autophagy-independent. Lastly, NSC 689534/Cu2+ was shown to have activity in an HL60 xenograft model. These data suggest that NSC 689534/Cu2+ is a potent oxidative stress inducer worthy of further preclinical investigation.

Hancock, Chad N.; Stockwin, Luke H.; Han, Bingnan; Divelbiss, Raymond D.; Jun, Jung Ho; Malhotra, Sanjay V.; Hollingshead, Melinda G.; Newton, Dianne L.

2010-01-01

185

Three novel compounds of 5-trifluoromethoxy-1H-indole-2,3-dione 3-thiosemicarbazone: Synthesis, crystal structures and molecular interactions  

NASA Astrophysics Data System (ADS)

5-Trifluoromethoxy-1H-indole-2,3-dione 3-(N-ethyl/benzylthiosemicarbazone) (2a/2b) and 5-trifluoromethoxy-1-morpholinomethyl-1H-indole-2,3-dione 3-(N-ethylthiosemicarbazone) (3a) were synthesized. The structures of the compounds were confirmed by elemental analysis, spectral data and X-ray single crystal diffraction analysis. The morpholin ring which adopts chair conformation and ethylamino group of 3a are disordered over two sets of sites with unequal occupancy. The indole heterocycle is nearly planar and the dihedral angle between the pyrrole and the adjacent phenyl ring is 2.09° (in 2a), 4.61° (in 2b) and 2.16° (in 3a). In all three crystal structures, a strong Nsbnd H···O hydrogen bond links the flat conjugated Hsbnd Nsbnd Ndbnd Csbnd Cdbnd O fragment into a six-membered ring. The molecules 2a, 2b and 3a have potential groups of proton donors (thiosemicarbazone group) available for hydrogen bonding. The structures 2b and 3a consist of isolated molecules, while that of 2a contains dimers formed by Csbnd H⋯O hydrogen bonds. The molecules are linked into three dimensional framework structure by a combination of mainly Nsbnd H⋯N and Nsbnd H⋯O hydrogen bonds and weak Csbnd F⋯? and ?⋯? interactions.

Kaynak, Filiz Betül; Özbey, Süheyla; Karal?, Nilgün

2013-10-01

186

Halo-substituted thiosemicarbazones and their copper(II), nickel(II) complexes: detailed spectroscopic characterization and study of antitumour activity against HepG2 human hepatoblastoma cells.  

PubMed

Copper(II) and nickel(II) complexes of two different halogen substituted thiosemicarbazone ligands were synthesized. The ligands 3,4-difluoroacetophenone thiosemicarbazone (1) and 2-bromo-4'-chloroacetophenone thiosemicarbazone (2) were characterized and confirmed spectroscopically by FT-IR, FT-Raman, UV-vis and fluorescence spectral analysis, while the respective copper(II) complexes [Cu(C9H9N3F2S)2Cl2] (1a), [Cu(C9H9N3ClBrS)2Cl2] (2a) and nickel(II) complexes [Ni(C9H9N3F2S)2] (1b), [Ni(C9H9N3ClBrS)2] (2b) were characterized by FT-IR, UV-vis and electron paramagnetic spectroscopy (EPR). The EPR spectra of the Cu(II) complexes provided the rhombic octahedral and axial symmetry of the complexes 1a and 2a respectively. For the complex 1a, the g values calculated as g1=2.1228, g2=2.0706 and g3=2.001 between 2900 and 3300 G. While for the complex 2a, a set of two resonance absorptions were observed. The synthesized compounds were tested for antitumor activity and showed that the ability to kill liver cancer cells significantly. Out of all the synthesized compounds, copper(II) complexes 1a and 2a showed high cytotoxic effect on liver cancer cells with 67.51% and 42.77% of cytotoxicity respectively at 100 ?M. PMID:24084484

Jagadeesh, M; Kalangi, Suresh K; Sivarama Krishna, L; Reddy, A Varada

2014-01-24

187

Mn(II), Co(II), Zn(II), Fe(III) and U (VI) complexes of 2-acetylpyridine 4 N-(2-pyridyl) thiosemicarbazone (HAPT); structural, spectroscopic and biological studies  

Microsoft Academic Search

The present work carried out a study on transition metal ion complexes which have been synthesized from 2-acetylpyridine 4N-(2-pyridyl) thiosemicarbazone (HAPT) 1. These complexes namely [Zn(HAPT)Cl2] 2, [Mn (HAPT)Cl2] 3, [Co (HAPT)Cl2] 4, [Fe(APT)Cl2(H2O)] 5 and [UO2(HAPT)(OAc)2] 6, were characterized by elemental analysis, spectral (IR, 1H NMR and UV–vis) and magnetic moment measurements. Thermal properties and decomposition kinetics of all

Usama El-Ayaan; Magdy M. Youssef; Shar Al-Shihry

2009-01-01

188

Phase I trial of pelvic radiation, weekly cisplatin, and 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP, NSC #663249) for locally advanced cervical cancer  

PubMed Central

Purpose This study assessed the safety/tolerability, pharmacokinetics, and clinical activity of three-times weekly intravenous 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP, NSC #663249) in combination with once weekly intravenous cisplatin and daily pelvic radiation in patients with gynecologic malignancies. 3-AP is a novel small molecule inhibitor of ribonucleotide reductase (RNR) and is being tested as a potential radiosensitizer and chemosensitizer. Experimental Design Patients with stage IB2-IVB cervical cancer (n=10) or recurrent uterine sarcoma (n=1) were assigned to dose-finding cohorts of 2-hour 3-AP infusions during five weeks of cisplatin chemoradiation. Pharmacokinetic and methemoglobin samples and tumor biopsy for RNR activity were obtained on days 1 and 10. Clinical response was assessed. Results The maximum tolerated 3-AP dose is 25mg/m2 given three-times weekly during cisplatin and pelvic radiation. Two patients experienced manageable 3-AP-related grade 3 or 4 electrolyte abnormalities. 3-AP pharmacokinetics showed a 2-hour half-life, with median peak plasma concentrations of 277ng/mL (25mg/m2) and 467ng/mL (50mg/m2). Median methemoglobin levels peaked at 1% (25mg/m2) and 6% (50mg/m2) at 4 hours after initiating 3-AP infusions. No change in RNR activity was found on day 1 versus 10 in six early complete responders, while elevated RNR activity was seen on day 10 as compared to day 1 in four late complete responders (P =0.02). Ten (100%) patients with stage IB2-IVB cervical cancer achieved complete clinical response and remain without disease relapse with a median 18 months of follow-up (6-32 months). Conclusions 3-AP was well tolerated at a three-times weekly intravenous 25mg/m2 dose during cisplatin and pelvic radiation.

Kunos, Charles A.; Waggoner, Steven; von Gruenigen, Vivian; Eldermire, Elisa; Pink, John; Dowlati, Afshin; Kinsella, Timothy J.

2009-01-01

189

Thiosemicarbazone Cu(II) and Zn(II) complexes as potential anticancer agents: Syntheses, crystal structure, DNA cleavage, cytotoxicity and apoptosis induction activity.  

PubMed

Four novel thiosemicarbazone metal complexes, [Cu(Am4M)(OAc)]·H2O (1), [Zn(HAm4M)Cl2] (2), [Zn2(Am4M)2Br2] (3) and [Zn2(Am4M)2(OAc)2]·2MeOH (4) [HAm4M=(Z)-2-(amino(pyridin-2-yl)methylene)-N-methylhydrazinecarbothioamide], have been synthesized and characterized by X-ray crystallography, elemental analysis, ESI-MS and IR. X-ray analysis revealed that complexes 1 and 2 are mononuclear, which possess residual coordination sites for Cu(II) ion in 1 and good leaving groups (Cl(-)) for Zn(II) ion in 2. Both 3 and 4 displayed dinuclear units, in which the metal atoms are doubly bridged by S atoms of two Am4M(-) ligands in 3 and by two acetate ions in bi- and mono-dentate forms, respectively, in 4. Their antiproliferative activities on human epithelial cervical cancer cell line (HeLa), human liver hepatocellular carcinoma cell line (HepG-2) and human gastric cancer cell line (SGC-7901) were screened. Inspiringly, IC50 value (11.2±0.9?M) of complex 1 against HepG-2 cells was nearly 0.5 fold of that against human hepatic cell lines LO2, showing a lower toxicity to human liver cells. Additionally, it displayed a stronger inhibition on the viability of HepG-2 cells than cisplatin (IC50=25±3.1?M), suggesting complex 1 might be a potential high efficient antitumor agent. Furthermore, fluorescence microscopic observation and flow cytometric analysis revealed that complex 1 could significantly suppress HepG-2 cell viability and induce apoptosis. Several indexes, such as DNA cleavage, reactive oxygen species (ROS) generation, comet assay and cell cycle analysis indicated that the antitumor mechanism of complex 1 on HepG-2 cells might be via ROS-triggered apoptosis pathway. PMID:24690556

Shao, Jia; Ma, Zhong-Ying; Li, Ang; Liu, Ya-Hong; Xie, Cheng-Zhi; Qiang, Zhao-Yan; Xu, Jing-Yuan

2014-07-01

190

DNA, protein binding, cytotoxicity, cellular uptake and antibacterial activities of new palladium(II) complexes of thiosemicarbazone ligands: effects of substitution on biological activity.  

PubMed

The coordination propensities of 4(N,N')-diethylaminosalicylaldehyde-4(N)-substituted thiosemicarbazones (H(2)L(1-4)) were investigated by reacting with an equimolar amount of [PdCl(2)(PPh(3))(2)]. The new complexes were characterized by various spectroscopic techniques. The structure determination of the complexes [Pd(DeaSal-tsc)(PPh(3))] (1), [Pd(DeaSal-mtsc)(PPh(3))] (2) and [Pd(DeaSal-etsc)(PPh(3))] (3) by X-ray crystallography showed that ligands are coordinated in a dibasic tridentate ONS donor fashion forming stable five and six membered chelate rings. The binding ability of complexes (1-4) to calf-thymus DNA (CT DNA) has been explored by absorption and emission titration methods. Based on the observations, an electrostatic and an intercalative binding mode have been proposed. The protein binding studies have been monitored by quenching of tryptophan and tyrosine residues in the presence of complexes using lysozyme as a model protein. As determined by MTT assays, complex 3 exhibited a higher cytotoxic effect towards human lung cancer cell line (A549) and liver cancer cells (HepG2). LDH, NO assay and cellular uptake of the complexes have been studied. Further, antibacterial activity studies of the complexes have been screened against the pathogenic bacteria such as Enterococcus faecalis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa, MIC50 values of the complexes showed that the complexes exhibited significant activity against the pathogens and among the complexes, 3 exhibited higher activity. PMID:22051854

Kalaivani, P; Prabhakaran, R; Dallemer, F; Poornima, P; Vaishnavi, E; Ramachandran, E; Padma, V Vijaya; Renganathan, R; Natarajan, K

2012-01-01

191

A phase 2 consortium (P2C) trial of 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP) for advanced adenocarcinoma of the pancreas.  

PubMed

3-Aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP, Triapine) is a novel small molecule inhibitor of ribonucleotide reductase (RR) with clinical signs of activity in pancreatic cancer. Therefore, the Phase 2 Consortium (P2C) initiated a trial (two single stage studies with planned interim analysis) of 3-AP at 96 mg/m(2) intravenously days 1-4 and 15-18 of a 28-day cycle in both chemotherapy-naive and gemcitabine-refractory (GR) patients with advanced pancreatic cancer. The primary endpoint was survival at six months (chemotherapy-naive) and four months (GR). Secondary endpoints were toxicity, response, overall survival, time to progression and mechanistic studies. Fifteen patients were enrolled including one chemotherapy-naïve and 14 GR. The chemotherapy-naïve patient progressed during cycle 1 with grade 3 and 4 toxicities. Of 14 GR patients, seven received two cycles, six received one cycle and one received eight cycles. Progression precluded further treatment in 11 GR patients. Additionally, one died of an ileus in cycle 1 considered related to treatment and two stopped treatment due to toxicity. Five GR patients had grade 4 toxicities possibly related to 3-AP and six GR patients had grade 3 fatigue. Toxicities and lack of meaningful clinical benefit prompted early study closure. Four-month survival in GR patients was 21% (95% CI: 8-58%). Correlative studies confirmed that 3-AP increased the percentage of S-phase buccal mucosal cells, the presence of multidrug resistance gene polymorphisms appeared to predict leukopenia, and baseline pancreatic tumor RR M2 expression was low relative to other tumors treated with 3-AP. In conclusion, this regimen appears inactive against predominantly GR pancreatic cancer. RR M2 protein may not have a critical role in the malignant potential of pancreatic cancer. PMID:18278438

Attia, Steven; Kolesar, Jill; Mahoney, Michelle R; Pitot, Henry C; Laheru, Daniel; Heun, James; Huang, Wei; Eickhoff, Jens; Erlichman, Charles; Holen, Kyle D

2008-08-01

192

Vibrational spectroscopy (FT-IR and Laser-Raman) investigation, and computational (M06-2X and B3LYP) analysis on the structure of 4-(3-fluorophenyl)-1-(propan-2-ylidene)-thiosemicarbazone  

NASA Astrophysics Data System (ADS)

In this study, the experimental and theoretical vibrational spectral analysis of 4-(3-fluorophenyl)-1-(propan-2-ylidene)-thiosemicarbazone have been carried out. The experimental FT-IR (4000-400 cm-1) and Laser-Raman spectra (4000-100 cm-1) have been recorded for the solid state samples. The theoretical vibrational frequencies and the optimized geometric parameters (bond lengths and angles) have been calculated for gas phase using density functional theory (DFT/B3LYP: Becke, 3-parameter, Lee-Yang-Parr) and M06-2X (the highly parametrized, empirical exchange correlation function) quantum chemical methods with 6-311++G(d,p) basis set. The diversity in molecular geometry of fluorophenyl substituted thiosemicarbazones has been discussed based on the X-ray crystal structure reports and theoretical calculation results from the literature. The assignments of the vibrational frequencies have been done on the basis of potential energy distribution (PED) analysis by using VEDA4 software. A good correlation was found between the computed and experimental geometric and vibrational data. In addition, the highest occupied (HOMO) and lowest unoccupied (LUMO) molecular orbital energy levels and other related molecular energy values of the compound have been determined using the same level of theoretical calculations.

Sert, Yusuf; Miroslaw, Barbara; Ç?rak, Ça?r?; Do?an, Hatice; Szulczyk, Daniel; Struga, Marta

2014-07-01

193

Syntheses and extraction properties of novel biscalixarene and thiacalix[4]arene hydrazone derivatives  

Microsoft Academic Search

By reacting thiacalix[4]arene with p-tosyloxyethoxylbenzaldehyde 1, 3-bis(benzaldehyde-4-oxyethyloxy)-p-tert-butylthiacalix[4]arene (2) were prepared in yield of 65%. Refluxing compound 2 with aniline, salicylic hydrazide, nicotinic hydrazide and isonicotinic hydrazide, novel ringopening 1,3-bis-arylformyl-hydrazone substituted thiacalix[4]arene derivatives (3a–3d) were obtained in yields of 77–89%. Refluxing compound 2 with o-phenylendiamine, oxalyl dihydrazide, malonic dihydrazide and adipic dihydrazide in “1 + 1” intermolecular condensation mode\\u000a under diluted condition, novel

Fafu Yang; Xia Zhao; Hongyu Guo; Jianrong Lin; Zhaohui Liu

2008-01-01

194

Monitoring the pH-Dependent Oximation of Methyl Ethyl Ketone and Benzaldehyde by in situ Fourier Transform IR Spectroscopy in a Heterogeneous Liquid-Liquid Two-Phase System  

Microsoft Academic Search

In situ Fourier transform IR spectroscopy was a useful tool in monitoring the pH-dependent and two-step oximation of methyl ethyl ketone and benzaldehyde in a liquid–liquid two-phase system, one phase of which was water. Carrying out the oximations at pH 8, the oximation was complete within 45 min and the corresponding carbonyl compound–hydroxylamine adduct (2) could be detected as an intermediate,

Gyorgy Keglevich; Istvan Csontos; Nikolett Szilagyi

2009-01-01

195

Structure-activity relationships for metal-labeled blood flow tracers: comparison of keto aldehyde bis(thiosemicarbazonato)copper(II) derivatives.  

PubMed

Radiocopper-labeled pyruvaldehyde bis(N4-methylthiosemicarbazonato)copper(II), Cu[PTSM], is under investigation as a radiopharmaceutical for evaluation of regional blood flow in the brain, heart, and kidneys because it affords relatively high levels of radioactivity in these organs upon intravenous injection, followed by prolonged tissue retention of the radiolabel. To probe and differentiate the physicochemical properties that are critical for blood-brain barrier (BBB) penetration and tissue retention in complexes of this type, 17 67Cu-labeled copper(II) bis(thiosemicarbazone) derivatives of Cu[PTSM] have been prepared and characterized, focusing on the bis(thiosemicarbazone), bis(N4-methylthiosemicarbazone), bis(N4-dimethylthiosemicarbazone), and bis(N4-ethylthiosemicarbazone) derivatives of several alkylglyoxals (R(1) = Me, Et, n-Pr, i-Pr, n-Bu, or Me(EtO)CH) and phenylglyoxal. The compounds studied varied in lipophilicity from log P = 0.75 to log P = 3.5 (where P is the octanol/water partition coefficient). In rat biodistribution studies the N4-methylthiosemicarbazone (R(1)TSM) and N4-dimethylthiosemicarbazone (R(1)TSM2) complexes always show comparable cerebral uptake at 1 min postinjection (iv) for any given R(1) group, while the thiosemicarbazone (R(1)TS) complex always penetrates the BBB less efficiently. Comparison of the various Cu[R(1)TS] derivatives shows that their brain uptake does tend to increase with increasing lipophilicity over the range 0.75 less than log P less than 2.4, although it never reaches that of the N4-alkylated derivatives. The Cu[R(1)TS] and Cu[R(1)TSM] complexes are found to exhibit prolonged cerebral retention of activity, consistent with their known susceptibility to reductive decomposition by intracellular sulfhydryl groups, while the more inert Cu[R(1)TSM2] complexes clear from the brain relatively rapidly. Tracer clearance kinetics in the heart and kidney are similar to those observed for the brain with each of the tracers examined. PMID:2342070

John, E K; Green, M A

1990-06-01

196

High efficient photocatalytic selective oxidation of benzyl alcohol to benzaldehyde by solvothermal-synthesized ZnIn2S4 microspheres under visible light irradiation  

NASA Astrophysics Data System (ADS)

Hexagonal ZnIn2S4 samples have been synthesized by a solvothermal method. Their properties have been determined by X-ray diffraction, ultraviolet-visible-light diffuse reflectance spectra, field emission scanning electron microscopy, nitrogen adsorption-desorption and X-ray photoelectron spectra. These results demonstrate that ethanol solvent has significant influence on the morphology, optical and electronic nature for such marigold-like ZnIn2S4 microspheres. The visible light photocatalytic activities of the ZnIn2S4 have been evaluated by selective oxidation of benzyl alcohol to benzaldehyde using molecular oxygen as oxidant. The results show that 100% conversion along with >99% selectivity are reached over ZnIn2S4 prepared in ethanol solvent under visible light irradiation (?>420 nm) of 2 h, but only 58% conversion and 57% yield are reached over ZnIn2S4 prepared in aqueous solvent. A possible mechanism of the high photocatalytic activity for selective oxidation of benzyl alcohol over ZnIn2S4 is proposed and discussed.

Chen, Zhixin; Xu, Jingjing; Ren, Zhuyun; He, Yunhui; Xiao, Guangcan

2013-09-01

197

Synthesis, spectroscopic investigations and computational study of 4-((9,10-dioxo-9,10-dihydroanthracen-1-yl)oxy)benzaldehyde  

NASA Astrophysics Data System (ADS)

The molecular structure, vibrational frequencies, corresponding vibrational assignments of 4-((9,10-dioxo-9,10-dihydroanthracen-1-yl)oxy)benzaldehyde in “trans” and “ana” forms have been investigated by UV-Vis, FT-IR and NMR spectroscopy as well as density functional theory (DFT) B3LYP method with 6-311++G(d,p) basis set. The vibrational analysis of the two forms of cited compound was performed by means of infrared absorption spectroscopy in combination with theoretical simulations. The obtained geometrical parameters and wavenumbers of vibrational normal modes from the DFT method were in good consistency with the experimental values. The 1H and 13C nuclear magnetic resonance (NMR) chemical shifts of the molecule were calculated by GIAO method. Computed molecular orbital and time dependent DFT oscillator renderings agree closely with experimental observations. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. In order to predict the reactive sites, a molecular electrostatic potential map (MEP) for the title compound was obtained. Transition structures were calculated by QST3 and IRC methods which yielded the potential energy surface and activation energy.

Kanaani, A.; Ajloo, D.; Kiyani, H.; Farahani, M.

2014-04-01

198

Formation of active products of benzaldehyde dimethane sulfonate (NSC 281612, DMS612) in human blood and plasma and their activity against renal cell carcinoma lines  

PubMed Central

Benzaldehyde dimethane sulfonate (BEN, DMS612, NSC281612) is an alkylating agent with activity against renal cell carcinoma and is being evaluated clinically. To support clinical trials, we developed an LC–MS/MS assay to detect and quantitate BEN and its metabolites/decomposition products. We tested the stability and products of BEN and benzoic acid dimethane sulfonate (BA) in plasma, blood and five renal carcinoma cell lines in vitro. Further, we determined the IC50 of BEN, BA and four of their products in these cell lines. Low temperature and pH stabilized the analytes, and utilizing this resulted in an accurate, precise and reproducible assay. The half-lives of BEN and BA added to plasma in vitro were 220 and 5 min, while the half-life of BEN in whole blood was 18 min. The generation and degradation of up to 12 analytes were monitored, and structures confirmed with available authentic standards. The IC50 for BEN was 5- to 500-fold lower than that of any of its products, while the cellular metabolic activity toward BEN correlated with ALDH activity and IC50 values. We detected six of the in vitro products and their respective glucuronides in murine plasma after dosing BEN. The information gained from these experiments will be instrumental in the evaluation of the pharmacology of BEN in ongoing human trials.

Parise, Robert A.; Anyang, Bean N.; Eiseman, Julie L.; Egorin, Merrill J.; Covey, Joseph M.; Beumer, Jan H.

2012-01-01

199

Formation of active products of benzaldehyde dimethane sulfonate (NSC 281612, DMS612) in human blood and plasma and their activity against renal cell carcinoma lines.  

PubMed

Benzaldehyde dimethane sulfonate (BEN, DMS612, NSC281612) is an alkylating agent with activity against renal cell carcinoma and is being evaluated clinically. To support clinical trials, we developed an LC-MS/MS assay to detect and quantitate BEN and its metabolites/decomposition products. We tested the stability and products of BEN and benzoic acid dimethane sulfonate (BA) in plasma, blood and five renal carcinoma cell lines in vitro. Further, we determined the IC(50) of BEN, BA and four of their products in these cell lines. Low temperature and pH stabilized the analytes, and utilizing this resulted in an accurate, precise and reproducible assay. The half-lives of BEN and BA added to plasma in vitro were 220 and 5 min, while the half-life of BEN in whole blood was 18 min. The generation and degradation of up to 12 analytes were monitored, and structures confirmed with available authentic standards. The IC(50) for BEN was 5- to 500-fold lower than that of any of its products, while the cellular metabolic activity toward BEN correlated with ALDH activity and IC(50) values. We detected six of the in vitro products and their respective glucuronides in murine plasma after dosing BEN. The information gained from these experiments will be instrumental in the evaluation of the pharmacology of BEN in ongoing human trials. PMID:23053264

Parise, Robert A; Anyang, Bean N; Eiseman, Julie L; Egorin, Merrill J; Covey, Joseph M; Beumer, Jan H

2013-01-01

200

Synthesis, characterization and antitumor activity of polymeric copper(II) complexes with thiosemicarbazones of 3-methyl-5-oxo-1-phenyl-3-pyrazolin-4-carboxaldehyde and 5-oxo-3-phenyl-3-pyrazolin-4-carboxaldehyde.  

PubMed

New polymeric copper(II) complexes with two tridentate ONS thiosemicarbazone ligands containing substituted pyrazolone moiety were synthesized and characterized by means of spectroscopic, electrochemical and crystallographic techniques. While both ligands exist as different tautomers in the solid state and DMSO-d(6) solution, Cu(II) ion coordinates the ligands from the same tautomeric form with square-pyramidal geometry around each Cu atom. In the crystal structures, the copper(II) complex cation forms polymeric chains {[Cu(L)Cl](+)}(n) with a bridging chlorine atom. One of the complexes was found to have a significantly higher cytotoxic potential in comparison with cisplatin in inhibition of several cell lines (HL60, REH, C6, L929 and B16). The results obtained on the basis of flow cytometry indicated that apoptosis could be possible mechanism of cell death. PMID:21955843

Leovac, Vukadin M; Bogdanovi?, Goran A; Jovanovi?, Ljiljana S; Joksovi?, Ljubinka; Markovi?, Violeta; Joksovi?, Milan D; Den?i?, Sonja Misirli?; Isakovi?, An?elka; Markovi?, Ivanka; Heinemann, Frank W; Trifunovi?, Sre?ko; ?alovi?, Ivica

2011-11-01

201

Efficient and versatile catalysis of N-alkylation of heterocyclic amines with alcohols and one-pot synthesis of 2-aryl substituted benzazoles with newly designed ruthenium(ii) complexes of PNS thiosemicarbazones.  

PubMed

Ruthenium(ii) carbonyl complexes with phosphine-functionalized PNS type thiosemicarbazone ligands [RuCl(CO)(EPh3)(L)] (1-6) (E = P or As, L = 2-(2-(diphenylphosphino)benzylidene) thiosemicarbazone (PNS-H), 2-(2-(diphenylphosphino)benzylidene)-N-methylthiosemicarbazone (PNS-Me), 2-(2-(diphenylphosphino)benzylidene)-N-phenylthiosemicarbazone (PNS-Ph)) have been synthesized and characterized by elemental analysis and spectroscopy (IR, UV-Vis, (1)H, (13)C, (31)P-NMR) as well as ESI mass spectrometry. The molecular structures of complexes 1, 2 and 6 were identified by means of single-crystal X-ray diffraction analysis. The analysis revealed that all the complexes possess a distorted octahedral geometry with the ligand coordinating in a uni-negative tridentate PNS fashion. All the ruthenium complexes (1-6) were tested as catalyst for N-alkylation of heteroaromatic amines with alcohols. Notably, complex 2 was found to be a very efficient and versatile catalyst towards N-alkylation of a wide range of heterocyclic amines with alcohols. Complex 2 can also catalyze the direct amination of 2-nitropyridine with benzyl alcohol to the corresponding secondary amine. Furthermore, a preliminary examination of performance for N,N-dialkylation of diamine showed promising results, giving good conversion and high selectivity. In addition, N-alkylation of ortho-substituted anilines (-NH2, -OH and -SH) led to the one-pot synthesis of 2-aryl substituted benzimidazoles, benzoxazoles and benzothiazoles, also revealing the catalytic activity of complex 2. PMID:24705796

Ramachandran, Rangasamy; Prakash, Govindan; Selvamurugan, Sellappan; Viswanathamurthi, Periasamy; Malecki, Jan Grzegorz; Ramkumar, Venkatachalam

2014-06-01

202

New approaches for the synthesis of thiophene derivatives with anti-tumor activities.  

PubMed

The reaction of either cyclohexanone or cyclopentanone with cyanoacetylhydrazine and elemental sulfur gave the 2-aminocycloalkeno[b]thiophene derivatives 3a and 3b, respectively. The latter compounds reacted with either aromatic benzaldehydes or active methylene reagents to give the Schiff's bases 5a-d and the pyrazole derivatives 7a-d and 9a-d, respectively. On the other hand, the reaction of 3-oxo-N-p-tolylbutanamide (10) with either of malononitrile or ethyl cyanoacetate gave the thiophene derivatives 13a and 13b, respectively. Compounds 13a,b were subjected to a series of heterocyclization reactions to give heterocyclic derivatives. Their cytotoxicity against the three human tumor cells lines, namely breast adenocarcinoma (MCF-7), non-small cell lung cancer (NCI-H460) and CNS cancer (SF-268) together against the normal human cell line namely the normal fibroblast cells WI 38 were measured. PMID:24169713

Mohareb, Rafat M; Abbas, Nermeen S; Ibrahim, Rehab A

2013-01-01

203

Inhibition of Helicobacter pylori growth and its cytotoxicity by 2-hydroxy 4-methoxy benzaldehyde of Decalepis hamiltonii (Wight & Arn); a new functional attribute.  

PubMed

Helicobacter pylori mediated gastric ulcer and cancers are common global problems since it was found to colonize in ?50% of gastric ulcer/cancer patients. Decalepis hamiltonii, (Asclepiadaceae family) extracts have been depicted with medicinal properties supporting the traditional knowledge of health beneficial attributes of D. hamiltonii. Previously we have shown that both aqueous as well as methanol extracts of D. hamiltonii containing abundant phenolics with predominant levels (20-40% of total phenolics) of 2-hydroxy-4-methoxy benzaldehyde (HMBA). Despite higher levels, HMBA contributed very little to the antioxidant activity (<10%) when compared to other phenolic compounds in the extract. In the current study we attempted to explore antimicrobial property, particularly anti-H. pylori activity, since traditional users document D. hamiltonii as a fighter of microbial infections. HMBA was isolated from the roots of D. hamiltonii by hydrodistillation and cold crystallization method; identified by HPLC and characterized using ESI-MS and confirmed by NMR studies as a compound of molecular mass 152 Da. Isolated HMBA was found to inhibit the growth of H. pylori, a potential ulcerogen in a dose dependent manner with MIC of ?39 ?g/mL as apposed to that of amoxicillin (MIC - 26 ?g/mL) for which H. pylori is susceptible. Results were further substantiated by the lysis of H. pylori by electron microscopy and electrophoretic studies. Studies on the mechanism of action indicated the counteracting effect of vacuolating toxin (VacA) of H. pylori which otherwise would lead to host cell cytotoxicity. Further the increased binding ability of HMBA to DNA and protein offered an impact on DNA protectivity and bioavailability. Results for the first time provide a direct evidence for anti-microbial attribute of HMBA. Insignificant antioxidant attribute of HMBA also reveals the anti-H. pylori activity via mechanisms other than antioxidative routes. PMID:21185348

Srikanta, Belagihalli M; Nayaka, Mysore A Harish; Dharmesh, Shylaja M

2011-04-01

204

Derivative couplings between TDDFT excited states obtained by direct differentiation in the Tamm-Dancoff approximation.  

PubMed

Working within the Tamm-Dancoff approximation, we calculate the derivative couplings between time-dependent density-functional theory excited states by assuming that the Kohn-Sham superposition of singly excited determinants represents a true electronic wavefunction. All Pulay terms are included in our derivative coupling expression. The reasonability of our approach can be established by noting that, for closely separated electronic states in the infinite basis limit, our final expression agrees exactly with the Chernyak-Mukamel expression (with transition densities from response theory). Finally, we also validate our approach empirically by analyzing the behavior of the derivative couplings around the [Formula: see text]/[Formula: see text] conical intersection of benzaldehyde. PMID:25028006

Ou, Qi; Fatehi, Shervin; Alguire, Ethan; Shao, Yihan; Subotnik, Joseph E

2014-07-14

205

Derivatives Page  

NSDL National Science Digital Library

Derivatives are financial securities whose value is derived from another "underlying" financial security. Options, futures, swaps, swaptions, and structured notes are all examples of derivative securities. Derivatives can be used in hedging, protecting against financial risk, or can be used to speculate on the movement of commodity or security prices, interest rates, or the levels of financial indices. The valuation of derivatives makes use of the statistical mathematics of uncertainty. With links to related articles. See also Derivatives Concepts A-Z, glossary of derivatives-related terminology designed to make the other articles in the Financial Pipeline's Derivatives section easier to understand.

2007-03-22

206

Mn(II), Co(II), Zn(II), Fe(III) and U (VI) complexes of 2-acetylpyridine 4N-(2-pyridyl) thiosemicarbazone (HAPT); structural, spectroscopic and biological studies  

NASA Astrophysics Data System (ADS)

The present work carried out a study on transition metal ion complexes which have been synthesized from 2-acetylpyridine 4N-(2-pyridyl) thiosemicarbazone (HAPT) 1. These complexes namely [Zn(HAPT)Cl 2] 2, [Mn (HAPT)Cl 2] 3, [Co (HAPT)Cl 2] 4, [Fe(APT)Cl 2(H 2O)] 5 and [UO 2(HAPT)(OAc) 2] 6, were characterized by elemental analysis, spectral (IR, 1H NMR and UV-vis) and magnetic moment measurements. Thermal properties and decomposition kinetics of all compounds are investigated. The interpretation, mathematical analysis and evaluation of kinetic parameters ( E, A, ? H, ? S and ? G) of all thermal decomposition stages have been evaluated using Coats-Redfern equation. The biochemical studies showed that, complexes 3 and 6 have powerful and complete degradation effect on the both DNA and protein. The SOD-like activity exhibited that complex 3 has a strong antioxidative properties. The antibacterial screening demonstrated that, the free ligand (HAPT), complexes 2, 3 and 6 have the maximum and broad activities against Gram-positive and Gram-negative bacterial strains.

El-Ayaan, Usama; Youssef, Magdy M.; Al-Shihry, Shar

2009-11-01

207

Synthesis, structure and antifungal activity of thiophene-2,3-dicarboxaldehyde bis(thiosemicarbazone) and nickel(II), copper(II) and cadmium(II) complexes: unsymmetrical coordination mode of nickel complex.  

PubMed

The reaction of nickel(II), copper(II) chlorides and cadmium(II) chloride and bromide with thiophene-2,3-dicarboxaldehyde bis(thiosemicarbazone) (2,3BTSTCH2) leads to a series of new complexes: [Ni(2,3BTSTCH)]Cl, [Cu(2,3BTSTC)], [CdCl2(2,3BTSTCH2)] and [CdBr2(2,3BTSTCH2)]. The crystal structures of the ligand and of [Ni(2,3BTSTCH)]Cl complex have been determined. In this case, we remark an unusual non-symmetrical coordination mode for the two functional groups: one acting as a thione and the second as a deprotonated thiolate. All compounds have been tested for their antifungal activity against human pathogenic fungi: Candida albicans, Candida glabrata and Aspergillus fumigatus, the cadmium complexes exhibit the highest antifungal activity. Cytotoxicity was evaluated using two biological methods: human MRC5 cultured cells and brine shrimp Artemia salina bioassay. PMID:23792913

Alomar, Kusaï; Landreau, Anne; Allain, Magali; Bouet, Gilles; Larcher, Gérald

2013-09-01

208

Discrete Derivatives  

NASA Astrophysics Data System (ADS)

The method of finite-differences is an important technique used to obtain numerical solutions to differential equations. Critical to the construction of such discrete models is how should the discrete representations of the derivatives be formulated? A prior, there exists many possibilities; examples, include the forward- and backward-Euler expressions, as well as various central-differences. However, it has become clear in recent years that the order of the discrete derivative must be the same as the particular order of the derivative appearing in the differential equation. If not, numerical instabilities will appear; these are solutions to the discrete equations that do not correspond to any solutions of the original differential equations. We show that discrete representations of first-derivatives can be constructed such that the elementary numerical instabilities do not occur. Our method generalizes the usual calculus based definition of the derivative. The general scalar ODE is used to illustrate our method.

Mickens, Ronald E.

2000-11-01

209

Thermophysical and thermoacoustical properties of benzaldehyde mixtures with ethylbenzene at 303.15, 308.15, and 313.15 K and a pressure of 0.1 MPa  

NASA Astrophysics Data System (ADS)

Ultrasound velocity ( u), density (?) and viscosity (?) measurements of benzaldehyde + ethylbenzene mixtures have been carried out at 303.15, 308.15, and 313.15 K. These values have been used to calculate the excess molar volume ( V E), deviation in viscosity (??), and deviation in isentropic compressibility (??s), deviations in ultrasound velocity (? u), excess free volume (? V f), excess intermolecular free length (? L f) and excess Gibbs free energy of activation of viscous flow (? G E). McAllister's three body interaction model is used for correlating kinematic viscosity of binary mixtures. The excess values were correlated using the Redlich-Kister polynomial equation to obtain their coefficients and standard deviations. The thermophysical properties under the study were fit to the Jouyban-Acree model. The observed variation of these parameters helps in understanding the nature of interactions in these mixtures. Further, theoretical values of the ultrasound speed were evaluated using theories and empirical relations.

Saravanakumar, K.; Lavanya, T. G.; Baskaran, R.; Kubendran, T. R.

2012-04-01

210

Spectroscopic studies and structure of 3-methoxy-2-[(2,4,4,6,6-pentachloro-1,3,5,2?5,4?5,6?5-triazatriphosphin-2-yl)oxy]benzaldehyde  

NASA Astrophysics Data System (ADS)

The compound called 3-methoxy-2-[(2,4,4,6,6-pentachloro-1,3,5,2?5,4?5,6?5-triazatriphosphin-2-yl)oxy]benzaldehyde has been synthesized from the reaction of 2-hydroxy-3-methoxybenzaldehyde with hexachlorocyclotriphosphazene. It has been characterized by elemental analysis, MS, IR, 1H NMR, 13C NMR, 31P NMR and UV-visible spectroscopic techniques. The structure of the title compound has been determind by X-ray analysis. Crystals are orthorhombic, space group P212121, Z = 4, a = 7.705(1), b = 12.624(1), c = 17.825(2) Å, R 1 = 0.0390 and wR 2 = 0.1074 [ I > 2?( I)], respectively.

Özay, H.; Yildiz, M.; Ünver, H.; Durlu, T. N.

2013-01-01

211

Synthesis, structural characterization and biological studies of copper complexes with 2-aminobenzothiazole derivatives  

NASA Astrophysics Data System (ADS)

Novel copper complexes of 2-aminobenzothiazole derivatives were synthesized by the condensation of Knoevenagel condensate acetoacetanilide (obtained from substituted benzaldehydes and acetoacetanilide) and 2-aminobenzothiazole. They were thoroughly characterized by elemental analysis, IR, 1H NMR, UV-Vis., MS Spectra, molar conductance, magnetic moment and electrochemical studies. These spectral studies suggested that distorted square planar geometry for all the complexes. Molar conductance data and magnetic susceptibility measurements provide evidence for monomeric and neutral nature of the complexes. The electrochemical behaviour of the ligand and complexes in DMSO at 298 K was studied. The present ligand systems stabilize the unusual oxidation states of copper ion during electrolysis. Antibacterial screening of the ligands and their complexes reveal that all the complexes show higher activities than the free ligands.

Joseph, J.; Boomadevi Janaki, G.

2014-04-01

212

Dichloridobis[3-(4-chloro-phen-yl)-2,N,N-trimethyl-2,3-di-hydro-1,2,4-oxa-diazole-5-amine-?N (4)]platinum(II)-4-chloro-benzaldehyde (1/1).  

PubMed

In the title 1:1 co-crystal, [PtCl2(C11H14ClN3O)2]·C7H5ClO, the coordination polyhedron of the Pt(II) atom is slightly distorted square-planar with the chloride and 2,3-di-hydro-1,2,4-oxa-diazole ligands mutually trans, as the Pt atom lies on an inversion center. The 4-chloro-benzaldehyde mol-ecules are statistically disordered about an inversion centre with equal occupancies for the two positions. The Pt(II) complex forms a three-dimensional structure through C-H?Cl and weaker C-H?O inter-actions with the 4-chloro-benzaldehyde mol-ecule. PMID:24109273

Kritchenkov, Andreii S; Gurzhiy, Vladislav V; Bokach, Nadezhda A; Kalibabchuk, Valentina A

2013-01-01

213

Synthesis and Antimicrobial Activity of Some New Quinoxaline Derivatives  

PubMed Central

2-Chloro-3-methylquinoxaline was selected as a nucleus around which various molecular transformations were performed to obtain new compounds expected to possess optimized antimicrobial activity. As very little work regarding attachment of ether linkages replacing chlorine at C-2 has been reported, it was thought worthwhile to synthesize various quinoxaline derivatives by replacing the C2 chlorine with an ether linkage attached to a benzene ring possessing an aldehyde or a free amino group which can be further reacted with aromatic amines and aromatic aldehydes, respectively, to yield new Schiff bases containing quinoxaline moieties. Thus the compounds 4-(2-methylquinoxalinyloxy) benzaldehyde (4), 2-[4-(substituted-benziminomethyl)-phenoxy]-3-methyl quinoxalines 5a–e, 4-(2-methyl-quinoxaline-3-yloxy)benzamine (6) and 4-(2-methylquinoxalin-3-yloxy)-N-substituted benzylidine benzamines 7a–e were synthesized and tested for their antimicrobial activity. The structures of the compounds were confirmed on the basis of their elemental and spectral data.

Singh, Dharmchand Prasad; Deivedi, Sanjay Kumar; Hashim, Syed Riaz; Singhal, Ram Gopal

2010-01-01

214

H2SO4-Promoted Synthesis of (E)-Stilbenes from Substituted Phenylacetones and Substituted Benzaldehydes Through Tandem Aldol–Grob Reaction  

Microsoft Academic Search

Stilbene derivates (stilbenoids) are present in plants and show a wide range of biological activities and potential therapeutic value. In continuation of our natural product synthesis program, an efficient, simple, and practical method has been developed to regioselectively synthesize (E)-stilbenes using H2SO4 as a catalyst in a short time (30–60 s) at room temperature in good to excellent yields.

T. Narender; K. Papi Reddy; Sriniwas Tiwari

2011-01-01

215

Glycopeptide derivatives.  

PubMed

Resistance to glycopeptides in enterococci, which first emerged in the late 1980's and is now widespread mainly in the United States, is posing a serious clinical problem due to the lack of alternative and efficacious therapeutic options, particularly against infections caused by VanA strains that are highly resistant to glycopeptides and almost all other antibiotics. In addition, isolates of Staphylococcus aureus, known as GISA, that are poorly susceptible to vancomycin and teicoplanin have been identified. Thus, there is an urgent need to develop new and more potent glycopeptides that are active against these problematic organisms. The following review will focus on the development of second-generation glycopeptides, namely LY333328 (Eli Lilly) and BI 397 (Biosearch Italia, in license to Versicor for North America), which are currently undergoing clinical trials in humans for their promising activity against VanA enterococci (LY333328), staphylococci (BI 397), and penicillin-resistant pneumococci. Both compounds were identified as the result of chemical programs that were aimed at pursuing activity of vancomycin-like or teicoplanin-like natural glycopeptides against VanA enterococci and multidrug-resistant staphylococci. More recent approaches toward glycopeptides modified in their heptapeptide core are also described. These include compounds in which amino acids 1 and 3 are replaced with other amino acid moieties such as in the modification of the asparagine side chain on residue 3 as well as attempts to change the structure of the heptapeptide backbone in positions that are critical for the molecular interaction with susceptible D-Ala-D-Ala and resistant D-Ala-D-Lactate targets. Covalently linked glycopeptide dimers and vancomycin derivatives in which vancosamine is suitably replaced with other sugar moieties will also be covered. PMID:11562292

Malabarba, A; Ciabatti, R

2001-12-01

216

A novel azo-aldehyde and its Ni(II) chelate; synthesis, characterization, crystal structure and computational studies of 2-hydroxy-5-{(E)-[4-(propan-2-yl)phenyl]diazenyl}benzaldehyde  

NASA Astrophysics Data System (ADS)

A novel azo-salicylaldeyde, 2-hydroxy-5-{(E)-[4-(propan-2-yl)phenyl]diazenyl} benzaldehyde and its Ni(II) chelate were obtained and characterized by analytical and spectral techniques. Molecular structure of the azo chromophore containing azo-aldehyde was determined by single crystal X-ray crystallography. X-ray data show that the compound crystallizes in the orthorhombic, Pbca space group with unit cell parameters a = 11.2706(9), b = 8.3993(7), c = 28.667(2) Å, V = 2713.7(4) Å3 and Z = 8. There is a strong phenol-aldehyde (OH⋯O) hydrogen bond forming a S(6) hydrogen bonding motif in the structure. There is also a weaker inter-molecular phenol-aldeyhde (OH⋯O) hydrogen bonding resulting in a dimeric structure and generating a D22(4) hydrogen bonding motif. Hydrogen bonded dimers are linked by ?–? interactions within the structure. The azo-aldehyde ligand behaved as bidentate, coordinating through the nitrogen atom of the azomethine group and or oxygen atom of phenolic hydroxyl group. Additionally, optimized structures of the three possible tautomers of the compound were obtained using B3LYP method with 6-311++G(d,p), 6-31G and 3-21G basis sets in the gas phase. B3LYP/6-311++G(d,p) level is found to be the best level for calculation. The electronic spectra of the compounds in the 200–800 nm range were obtained in three organic solvents.

Eren, Tu?ba; Kose, Muhammet; Sayin, Koray; McKee, Vickie; Kurtoglu, Mukerrem

2014-05-01

217

Novel cytochrome p450 bioactivation of a terminal phenyl acetylene group: formation of a one-carbon loss benzaldehyde and other oxidative products in the presence of N-acetyl cysteine or glutathione.  

PubMed

Compounds 1 (N1-(3-ethynylphenyl)-6-methyl-N5-(3-(6-(methylamino)pyrimidin-4-yl)pyridin-2-yl) isoquinoline-1,5-diamine) and 2 (N-(3-ethynylphenyl)-6,7-bis(2-methoxyethoxy)quinazolin-4-amine; Erlotinib/Tarceva) are kinase inhibitors that contain a terminal phenyl acetylene moiety. When incubated in the presence of P450 and NADPH, the anticipated phenyl acetic acid metabolite was formed. When 10 mM of N-acetyl-l-cysteine was added to the incubation mixtures, the phenyl acetic acid product was reduced and at 25 mM or higher concentration of NAC, formation of the phenyl acetic acid was abolished. Instead, the phenyl acetylene moiety lost a carbon and formed a benzaldehyde product. Other oxidation products incorporating one or more equivalents of NAC were also observed. The identities of the metabolites were characterized by MS and NMR. Addition of deferoxamine or ascorbic acid diminished the formation of the NAC influenced products. Similar products were also observed when 1 or 2 were incubated in P450 reactions supplemented with GSH, in Fenton reactions supplemented with NAC or GSH, and in peroxidase reactions supplemented with NAC. We propose the thiols act as a pro-oxidant readily undergoing a one-electron oxidation to form thiyl radicals which in turn initiates the formation of other peroxy radicals that drive the reaction to the observed products. These in vitro findings suggest that one-electron oxidation of thiols may promote the cooxidation of xenobiotic substrates. PMID:21395287

Subramanian, Raju; Tam, Janet; Aidasani, Divesh; Reid, Darren L; Skiles, Gary L

2011-05-16

218

Synthesis of tris-hydroxymethyl-based nitrone derivatives with highly reactive nitronyl carbon.  

PubMed

A novel series of ?-phenyl-N-tert-butyl nitrone derivatives, bearing a hydrophobic chain on the aromatic ring and three hydroxyl functions on the tert-butyl group, was synthesized through a short and convenient synthetic route based on a one-pot reduction/condensation of tris(hydroxymethyl)nitromethane with a benzaldehyde derivative. Because of the presence of hydroxyl functions on the tert-butyl group, an intramolecular Forrester-Hepburn reaction leading to the formation of an oxazolidine-N-oxyl compound was observed by electron paramagnetic resonance (EPR). The mechanism of cyclization was further studied by computational methods showing that intramolecular hydrogen bonding and high positive charge on the nitronyl carbon could facilitate the nucleophilic addition of a hydroxyl group onto the nitronyl carbon. At high nitrone concentrations, a second paramagnetic species, very likely formed by intermolecular nucleophilic addition of two nitrone molecules, was also observed but to a lesser extent. In addition, theoretical data confirmed that the intramolecular reaction is much more favored than the intermolecular one. These nitrones were also found to efficiently trap carbon-centered radicals, but complex spectra were observed due to the presence of oxazolidine-N-oxyl derivatives. PMID:22188016

Choteau, Fanny; Tuccio, Béatrice; Villamena, Frederick A; Charles, Laurence; Pucci, Bernard; Durand, Grégory

2012-01-20

219

Triapine and a more potent dimethyl derivative induce endoplasmic reticulum stress in cancer cells.  

PubMed

Triapine (3-AP; 3-aminopyridine-2-carboxaldehyde thiosemicarbazone), a ribonucleotide reductase inhibitor, has been extensively evaluated in clinical trials in the last decade. This study addresses the role of endoplasmic reticulum (ER) stress in the anticancer activity of 3-AP and the derivative N(4),N(4)-dimethyl-triapine (3-AP-Me), differing from 3-AP only by dimethylation of the terminal nitrogen. Treatment of colon cancer cells with 3-AP or 3-AP-Me activated all three ER stress pathways (PERK, IRE1a, ATF6) by phosphorylation of eIF2? and upregulation of gene expression of activating transcription factors ATF4 and ATF6. In particular, 3-AP-Me led to an upregulation of the alternatively spliced mRNA variant XBP1 (16-fold). Moreover, 3-AP and 3-AP-Me activated the cellular stress kinases c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinases, and inhibition of JNK activity antagonized the cytotoxic effect of both compounds. Subsequent to induction of the unfolded protein response, a significant upregulation of proapoptotic proteins was detected, including the transcription factor CHOP and Bim, an essential factor for ER stress-related apoptosis. In correlation with the higher degree of ER stress after 3-AP-Me treatment, also a more potent depolarization of mitochondrial membranes was found. These data suggest that 3-AP and 3-AP-Me induce apoptosis via ER stress. This was further corroborated by showing that inhibition of protein biosynthesis with cycloheximide prior to 3-AP and 3-AP-Me treatment leads to a significant reduction of the antiproliferative properties of both compounds. Taken together, this study demonstrates that induction of ER stress contributes to the mode of action of 3-AP and that terminal dimethylation leads to an even more pronounced manifestation of this effect. PMID:24378333

Trondl, Robert; Flocke, Lea S; Kowol, Christian R; Heffeter, Petra; Jungwirth, Ute; Mair, Georg E; Steinborn, Ralf; Enyedy, Éva A; Jakupec, Michael A; Berger, Walter; Keppler, Bernhard K

2014-03-01

220

Fluorescent sensors based on BODIPY derivatives for aluminium ion recognition: an experimental and theoretical study.  

PubMed

Two BODIPY derivative sensors for metal ion recognition containing 10-(4-hydroxyphenyl) (L1) and 10-(3,4-dihydroxyphenyl) (L2) were synthesized in a one-pot reaction of benzaldehyde derivative and 2,4-dimethylpyrrole in the presence of trifluoroacetic acid as catalyst. The binding abilities between these sensors and 50 equivalents of Na(+), K(+), Ag(+), Ca(2+), Fe(2+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+), Pb(2+), Al(3+) and Cr(3+) ions were studied using UV-vis and fluorescent spectroscopic methods. Of all the metal ions tested, Al(3+) ion showed the greatest decrease in intensity in the spectra of the sensors, and therefore Al(3+) ion forms the strongest complex. The binding abilities of BODIPY receptors with Na(+), Ag(+), Ca(2+), Co(2+), Ni(2+), Cu(2+), Zn(2+) and Al(3+) ions were also investigated using density functional theory (DFT) calculations at B3LYP/LanL2DZ theoretical level. The calculated results point to the same conclusion. DFT calculations also provided the HOMO-LUMO energy levels, which can explain the spectrum change upon complexation. PMID:23224941

Keawwangchai, Tasawan; Morakot, Nongnit; Wanno, Banchob

2013-03-01

221

2-Bromo-3-nitro-benzaldehyde  

PubMed Central

The title compound, C7H4BrNO3, was isolated as a by-product while attempting to prepare a diselenide. There is a close intra­molecular Br?O contact [2.984?(2)?Å]. The mol­ecules form loosely associated dimers held together by weak inter­molecular Br?O inter­actions with the nitro O atoms [Br?O = 3.179?(3)?Å]. As a result of these inter­actions, there is also a close Br?Br inter­molecular contact [3.8714?(6)?Å]. In addition, there are weak inter­molecular C—H?O inter­actions. The combination of these inter­actions produces sheets which propagate in the (210) and (10) directions perpendicular to c.

Singh, Vijay P.; Singh, Harkesh B.; Butcher, Ray J.

2009-01-01

222

Synthesis, characterization and thermal studies of binary and/or mixed ligand complexes of Cd(II), Cu(II), Ni(II) and Co(III) based on 2-(Hydroxybenzylidene) thiosemicarbazone: DNA binding affinity of binary Cu(II) complex.  

PubMed

A new series of metal complexes of Cd(II), Cu(II), Ni(II) and Co(III) with Schiff base ligand, H(2)L, 2-(Hydroxybenzylidene) thiosemicarbazone were synthesized. The mixed ligand complexes were prepared by using glycine (Gly), 2-aminopyridine (2-Ampy) and 1,10-phenanthroline (Phen) as secondary ligands. The structure of these complexes was identified and confirmed by elemental analysis, molar conductivity, UV-Vis, FT-IR and (1)H NMR spectroscopy and magnetic moment measurements as well as TG-DSC technique. The discussions of the prepared complexes indicate that the ligand behaves as a monoanionic tridentate ligand through ONS donor sites. Thermal studies suggested a mechanism for the degradation of the metal complexes as a function of temperature supporting the chelation modes and showed the possibility of obtaining new complexes pyrolytically in the solid state which cannot be synthesized from the solution. The absorption studies support that the binary Cu(II) complex exhibits a significant binding affinity to HS-DNA through intercalative mode. PMID:22446784

Saif, M; Mashaly, Mahmoud M; Eid, Mohamed F; Fouad, R

2012-06-15

223

Derivative Crystal Structures  

Microsoft Academic Search

There exists a class of crystal structures which are derived from others by generalization. These are here designated derivative structures. A special case of derivative structure is the popular ``superstructure.'' The symmetry of a derivative structure is a subgroup of the symmetry of the basic structure. Here the term ``subgroup'' is used in a wider sense than common in mathematical

M. J. Buerger

1947-01-01

224

Synthesis and molecular structures of (2-dialkylaminophenyl)alcohols and of 2-phenylaminoalkyl-dimethylaminobenzene derivatives  

Microsoft Academic Search

N,N-Dimethyl-o-toluidine, N,N-dimethylaniline, and N,N-diethylaniline were treated with n-butyllithium-tmeda in diethyl ether–hexane solution to give o-lithioarylamines, which react with various electrophiles (benzophenone, dicyclohexyl ketone, benzaldehyde, and Ph(H)C?NPh) to form the corresponding (2-dialkylaminophenyl)alcohols 1-HOCPh2-2-NMe2C6H4 (1), 1-HOCCy2-2-NMe2C6H4 (2), 1-HOCPh2CH2-2-NMe2C6H4 (4), 1-HOC(H)PhCH2-2-NMe2C6H4 (6), and 1-HOCPh2-2-NEt2C6H4 (7), and the 2-phenylaminoalkyl-dimethylaminobenzene derivatives 1-NMe2-2-NH(Ph)C(H)PhC6H4 (3) and 1-NMe2-2-NH(Ph)C(H)PhCH2C6H4 (5). Compounds 1–7 were characterized spectroscopically (NMR, IR, MS) and

Harbi Tomah Al-Masri; Joachim Sieler; Peter Lönnecke; Steffen Blaurock; Konstantin Domasevitch; Evamarie Hey-Hawkins

2004-01-01

225

Spectroscopic studies and structure of 3-methoxy-2 -[(2,4,4,6,6-pentachloro-1,3,5,2{lambda}{sup 5},4{lambda}{sup 5},6{lambda}{sup 5}-triazatriphosphin-2-yl)oxy] benzaldehyde  

SciTech Connect

The compound called 3-methoxy-2- [(2,4,4,6,6-pentachloro-1,3,5,2{lambda}{sup 5},4{lambda}{sup 5},6{lambda}{sup 5}-triazatriphosphin-2-yl)oxy] benzaldehyde has been synthesized from the reaction of 2-hydroxy-3-methoxybenzaldehyde with hexachlorocyclotriphosphazene. It has been characterized by elemental analysis, MS, IR, {sup 1}H NMR, {sup 13}C NMR, {sup 31}P NMR and UV-visible spectroscopic techniques. The structure of the title compound has been determind by X-ray analysis. Crystals are orthorhombic, space group P2{sub 1}2{sub 1}2{sub 1}, Z = 4, a = 7.705(1), b = 12.624(1), c = 17.825(2) A, R{sub 1} = 0.0390 and wR{sub 2} = 0.1074 [I > 2{sigma}(I)], respectively.

Oezay, H.; Yildiz, M., E-mail: myildiz@comu.edu.tr [Canakkale Onsekiz Mart University, Department of Chemistry, Faculty of Science and Arts (Turkey); Uenver, H.; Durlu, T. N. [Ankara University, Department of Physics, Faculty of Science (Turkey)] [Ankara University, Department of Physics, Faculty of Science (Turkey)

2013-01-15

226

Preparation of Benzofuran Derivatives.  

National Technical Information Service (NTIS)

The benzofuran derivatives exhibit estrogenic properties and are useful in animal husbandry, particularly as applied to steers which are grown for meat. The benzofuran derivatives are prepared by oxidizing flavylium salts.

L. Jurd

1965-01-01

227

Stereospecific Synthesis of Pyrrolidines with Varied Configurations via 1,3-Dipolar Cycloadditions to Sugar-Derived Enones.  

PubMed

Enantiomerically pure pyrrolidines have been obtained by 1,3-dipolar cycloaddition of stabilized azomethine ylides and sugar enones (dihydropyranones) derived from pentoses. Thus, the S-enone (menthyl 3,4-dideoxy-(1S)-pent-3-enopyranosid-2-ulose) was prepared from d-xylose, while the R analogue was obtained from l-arabinose. The dipoles were generated in situ from ?-arylimino esters of common amino acids (glycine, alanine, or phenylalanine) and aromatic aldehydes (benzaldehyde, 3-formylpyridine and 4-methoxybenzaldehyde). Under optimized conditions, the cycloaddition reactions were highly diastereo- and regioselective to yield, in most of the cases, a very major adduct of the 16 theoretically possible. The diastereoselectivity relies on the strict stereocontrol exerted by the stereogenic center of the pyranone. Thus, the (S)-enone, derived from d-xylose, gave tetrasubstituted pyrrolidines having a defined stereochemistry for the four stereocenters of the ring, while they had the opposite configuration when starting from the (R)-dihydropyranone. Furthermore, some endo-cycloadducts underwent isomerization of the carbons vicinal to the nitrogen atom to afford pyrrolidines with a rather unusual stereochemistry for the direct dipolar cycloadditions. PMID:24823371

Udry, Guillermo A Oliveira; Repetto, Evangelina; Varela, Oscar

2014-06-01

228

High affinity tamoxifen derivatives  

US Patent & Trademark Office Database

The synthesis of tamoxifen derivatives, most particularly halo, halo alkyl, hydroxy, and amino tamoxifen derivatives is disclosed. The native tamoxifen molecule includes a substituted chemical group positioned on the aliphatic chain of the tamoxifen molecule. Particular tamoxifen derivatives of the invention include chloro, bromo, iodo, fluoro, amino and DTPA tamoxifen derivatives, and corresponding lower alkyl halogenated forms. The halogenated tamoxifen derivatives possess superior binding affinities for estrogen receptor rich tissues, such as uterine tissue and breast tissue, relative to unsubstituted native tamoxifen. Radiolabeled forms of the tamoxifen derivatives may be used as highly specific imaging agents for estrogen receptor rich tissues. The fluoro and bromo tamoxifen derivatives are particularly useful for imaging estrogen receptors by PET whereas the iodinated tamoxifens are particularly useful in imaging estrogen receptors by SPECT. Rapid and efficient methods of preparing the tamoxifen derivatives having high specific activity (>6 Ci/.mu.mol) are also disclosed. Aliphatic chain substituted tamoxifen derivatives are shown to possess greater estrogen receptor binding affinity and more potent tumor cell inhibition than tamoxifen or tamoxifen derivatives substituted at other locations on the molecule (i.e., non-aliphatic chain substituted tamoxifen). The tanioxifen derivatives of the present invention may advantageously be used as anti-cancer therapeutic agents to halt estrogen-receptor positive tumors, such as those of breast and uterine tissue. The present invention also provides a hydrophilic DTPA-tamnoxifen analogue, and uses thereof in imaging estrogen receptor positive ER+ lesions.

2000-08-01

229

Coordination of Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), Pd(II) and Pt(II) with 2,5-hexanedione bis(thiosemicarbazone), HBTS: Crystal structure of cis-[Pd(HBTS)]Cl2 and 1-(2,5-dimethyl-1H-pyrrol-yl)-thiourea.  

PubMed

Metal complexes of Fe(3+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+), Hg(2+), Pd(2+) or Pt(2+) with 2,5-hexanedione bis(thiosemicarbazone), HBTS; have been prepared and spectroscopically investigated. The empirical formulae of the complexes were suggested based on the elemental analysis. Single crystal of Pd(II) has been solved to be cis-form of square-planar geometry by the X-ray crystallography. (1)H and (13)C NMR spectra have been recorded for HBTS, Zn(II), Cd(II), Hg(II), Pd(II) and Pt(II) complexes, in DMSO-d6, showing the mode of chelation. The ligand acts as a neutral or a binegative tetradentate (N2S2) or neutral bidentate on the basis of FT-IR. The magnetic moments and electronic spectra provide information about the geometry of the complexes which supported by calculating the ligand field parameters for the Co(II) and Fe(III) complexes. The Ni(II) complex has subnormal magnetic moment (0.71BM) indicative of a mixed stereochemistry of square-planar and tetrahedral structure. [Cu(HBTS-2H)] measured 0.93BM indicating high interaction between the copper centers. The ligand may be ordered at the top of the spectrochemical series which giving high ligand field splitting energy (10Dq=17,900cm(-1) for Co(2+) complex). The mass spectra of some complexes proved their stable chemical formulae while the TGA depicts the degradation steps and the final residue. In evaporating the mother liquor during the preparation of HBTS, new compound is obtained naming 1-(2,5-dimethyl-1H-pyrrol-yl)thiourea and its crystal was solved. PMID:24813284

Jeragh, Bakir; El-Asmy, Ahmed A

2014-09-15

230

Partial Derivatives: Geometric Visualization  

NSDL National Science Digital Library

This write-pair-share activity presents Calculus III students with a worksheet containing several exercises that require them to find partial derivatives of functions of two variables. Afterwards, a series of Web-based animations are used to illustrate the surface of each function, the path of the indicated partial derivative for a specified value of the variable and the value of the derivative at each point along the path.

Rutledge, James

231

Endohedral Metallofullerene Derivatives  

NASA Technical Reports Server (NTRS)

Trimetallic nitride endohedral metallofullerene derivatives and their preparation are described. The trimetallic nitride endohedral metallofullerene derivatives have the general formula A(sub 3-n)X(sub n)@C(sub m)(R) where n ranges from 0 to 3, A and X may be trivalent metals and may be either rare earth metal or group IIIB metals, m is between about 60 and about 200, and R is preferably an organic group. Derivatives where the R group forms cyclized derivatives with the fullerene cage are also described.

Dorn, Harry C. (Inventor); Iezzi, Erick B. (Inventor); Duchamp, James (Inventor)

2008-01-01

232

Acetylenic derivatives of heterocycles  

Microsoft Academic Search

1.The reaction for the catalytic replacement of halogen in the aromatic ring by the acetylenic moiety was extended to imidazole derivatives.2.In this reaction iodine in the 2 position of the imidazole ring is substantially more active than iodine in the 4 position.3.The mono- and diacetylenic derivatives of imidazole with a free acetylenic hydrogen were obtained.

M. S. Shvartsberg; L. N. Bizhan; I. L. Kotlyarevskii

1971-01-01

233

Partial Derivative Visualization Gallery  

NSDL National Science Digital Library

This resource is a small gallery of demos for illustrating partial derivatives geometrically. These animations can be used by instructors in a classroom setting or by students to aid in acquiring a visualization background for partial derivatives. Two file formats, gif and QuickTime files are used for the animations which can be downloaded.

Roberts, Lila F.; Hill, David R.

2004-11-11

234

Teaching Cournot without Derivatives.  

ERIC Educational Resources Information Center

Presents a simple technique for teaching the Cournot model to first-year microeconomic students. Involves demonstrating, without the use of derivatives, that out of all rectangles with a common perimeter, the square has the greatest area. (RLH)

Dufwenberg, Martin

2001-01-01

235

Preparation of Benzofuran Derivatives.  

National Technical Information Service (NTIS)

The benzofuran derivatives exhibit estrogenic properties and may be used in animal husbandry. Coumestrol is synthesized by reacting 2-(2,4-dihydroxyphenyl)-3-carboalkoxy-6-hydroxy benzofuran with a strong acid in the presence of water to cause hydrolysis ...

L. Jurd

1964-01-01

236

Epoxide-derived organosulfates  

NASA Astrophysics Data System (ADS)

Organosulfates (OS) are a significant fraction of secondary organic aerosol (SOA) material in the atmosphere. OS are typically surface-active, and have been suggested to cause surface tension depression in aerosols. Recent field studies suggest that epoxide-derived OS are the most abundant OS type in aerosols. Time-dependent surface tension measurements and Aerosol-CIMS characterization of two epoxides and their organosulfate products are shown. ?-pinene oxide, derived from ?-pinene, shows significant surface tension depression in H2O and ammonium sulfate. Results from cis-2,3-epoxybutane-1,4-diol (BEPOX), a butadiene-derived analog to isoprene-derived epoxydiols, are also shown. In addition, using GAMMA, a photochemical box model using coupled gas- and aqueous-phase chemistry developed in the McNeill laboratory, we show the dominance of epoxide-derived OS formation over other competing OS formation mechanisms, such as radical chemistry, under both high-NOx and low-NOx scenarios.

Schwier, A. N.; Woo, J.; McNeill, V. F.

2011-12-01

237

Semisynthetic Derivatives of Epothilones  

NASA Astrophysics Data System (ADS)

Semisynthetic derivatives of natural products traditionally occupy a prominent space in natural-product-based drug discovery (1, 2). As many biologically active natural products exhibit a high degree of structural complexity (3), the chemical derivatization of material isolated from natural sources often represents the only feasible means (or at least the only economically viable approach) to explore structure-activity-relationships (SAR) and to produce analogs with more favorable pharmacokinetic and pharmacological properties than the natural product lead. Examples of clinically important drugs that are semisynthetic derivatives of natural products exist in virtually all disease areas (1, 2); in the treatment of cancer this includes compounds such as etoposide or teniposide (derived from podophyllotoxin) (4-6), irinotecan and topotecan (derived from camptothecin) (7-9), or docetaxel (derived from 10-deacetylbaccatin III) (10, 11). Even for taxol (11), which is a natural product (12), the sustained supply of sufficient quantities of material for widespread clinical use could only be secured through the development of a semisynthetic production process from another natural product, namely, 10-deacetylbaccatin III (13). In light of these facts, it is not surprising that semisynthesis approaches have also featured prominently in the elucidation of the SAR for epothilones and in the discovery of a number of clinical development candidates.

Altmann, Karl-Heinz

238

Myeloid derived suppressor cells  

PubMed Central

The goal of achieving measurable response with cancer immunotherapy requires counteracting the immunosuppressive characteristics of tumors. One of the mechanisms that tumors utilize to escape immunosurveillance is the activation of myeloid derived suppressor cells (MDSCs). Upon activation by tumor-derived signals, MDSCs inhibit the ability of the host to mount an anti-tumor immune response via their capacity to suppress both the innate and adaptive immune systems. Despite their relatively recent discovery and characterization, anti-MDSC agents have been identified, which may improve immunotherapy efficacy.

Waldron, Todd J.; Quatromoni, Jon G.; Karakasheva, Tatiana A.; Singhal, Sunil; Rustgi, Anil K.

2013-01-01

239

Drawing Updates From Derivations  

Microsoft Academic Search

We propose a method for satisfying update requests in deductive databases. The setting is a generalization of the view update problem in relational databases. Updates can be drawn from goals and input clauses in derivations that are rooted at the request. An update may be invalidated by negation or integrity constraints. Thus, it may be necessary to try other updates,

Hendrik Decker; Siemens ZFE

1990-01-01

240

Functional Derivatives of Polyisobutene  

Microsoft Academic Search

The methods of synthesis of isobutene polymers with end groups of different types are examined. It is shown that advances in the synthesis of these compounds are associated with the progress in the field of the regulation of the cationic polymerisation and copolymerisation of isobutene and the degradation of isobutene polymers and copolymers. Examples of the employment of functional derivatives

Yu A. Sangalov; Yu B. Yasman

1985-01-01

241

Liquid crystalline cellulose derivatives  

SciTech Connect

Following the observation that (hydroxypropyl)cellulose in water forms an ordered cholesteric liquid crystalline phase at high polymer concentrations, reports that many other cellulose derivatives in a wide variety of solvents also form liquid crystalline solutions have appeared in the scientific and patent literature. A tabulation of cellulose-based liquid crystalline systems is presented. The formation of the ordered phase is attributed to the limited flexibility of the cellulose chain. However, some cellulose derivatives form liquid crystalline phases only in specific solvents; concentrated solutions in other solvents remain isotropic. Other cellulose derivatives, such as (hydroxypropyl)cellulose, appear to form liquid crystalline solutions in any solvent that dissolves sufficiently high concentrations of the polymer. It has been suggested that the role of flexible side-chain substituents is to allow the main chains to achieve their equilibrium orientational order. The presence of many large substituents on the cellulose backbone also increases the effective chain radius and may change the chain conformation. The effect of side-chain structure on the properties of cellulose liquid crystalline phases is thus of interest. A series of esters of (hydroxypropyl)cellulose have been prepared. In addition to forming liquid crystalline solutions in organic solvents, these materials also were found to form cholesteric thermotropic phases in the absence of solvent. The thermotropic phases show spontaneous molecular orientation and cholesteric reflection. On heating, a transformation to the isotropic melt occurs. The liquid crystalline state of cellulose and its derivatives is thus widely observed. 42 references, 4 figures, 3 tables.

Gray, D.G.

1983-01-01

242

Metal derivatives of tetrazoles  

NASA Astrophysics Data System (ADS)

Published data on the synthesis, structure, properties and applications of metal derivatives of tetrazoles are generalised and described systematically. Compounds based on the anionic and neutral tetrazole forms, C- and N-mono- and C,N-disubstituted tetrazoles are considered.

Gaponik, Pavel N.; Voitekhovich, Sergei V.; Ivashkevich, Oleg A.

2006-06-01

243

Amphetamine derivative related deaths  

Microsoft Academic Search

Amphetamine its methylendioxy (methylendioxyamphetamine methylenedioxymethylamphetamine, methylenedioxyethylamphetamine) and methoxy derivatives (p-methoxyamphetamine and p-methoxymethylamphetamine) are widely abused in Spanish society. We present here the results of a systematic study of all cases of deaths brought to the attention of the Madrid department of the Instituto Nacional de Toxicologia from 1993 to 1995 in which some of these drugs have been found in

C Lora-Tamayo; T Tena; A Rodr??guez

1997-01-01

244

Synthesis of pseudouridine derivatives  

Microsoft Academic Search

There are over one hundred modified nucleosides found in natural RNAs. Among them, pseudouridine is the most common type of modification found abundantly in RNA. Derivatives such as 1-methylpseudouridine, 3-methyl pseudouridine, and 1-methyl-3-(3-amino-3-carboxypropyl)pseudouridine are also found in nature. The overall structural and functional effects of these modified nucleosides remain unclear. Therefore, the study of these modifications is very important. The

Wantanee Sittiwong

2008-01-01

245

Functional Derivatives of Polyisobutene  

NASA Astrophysics Data System (ADS)

The methods of synthesis of isobutene polymers with end groups of different types are examined. It is shown that advances in the synthesis of these compounds are associated with the progress in the field of the regulation of the cationic polymerisation and copolymerisation of isobutene and the degradation of isobutene polymers and copolymers. Examples of the employment of functional derivatives of isobutene polymers in various branches of technology are presented. The bibliography includes 102 references.

Sangalov, Yu A.; Yasman, Yu B.

1985-07-01

246

Biomolecule derived nanostructured arrays  

Microsoft Academic Search

During the last decade, intensive research have been reported on biomimetic approaches towards achieving mono-dispersed nanoparticles, and building self-assembled system out of those (organizing nanoparticles). However the development of this research avenue is being hindered by the limited knowledge and very few practical, efficient, cost-effective approaches for implementation of the bio-derived arrays into engineering practice. The objective of this work

Zhen Yuan

2007-01-01

247

Reflexivity in derived categories  

Microsoft Academic Search

An adjoint pair of contravariant functors between abelian categories can be\\u000aextended to the adjoint pair of their derived functors in the associated\\u000aderived categories. We describe the reflexive complexes and interpret the\\u000aachieved results in terms of objects of the initial abelian categories. In\\u000aparticular we prove that, for functors of any finite cohomological dimension,\\u000athe objects of the

Francesca Mantese; Alberto Tonolo

2010-01-01

248

Computation of Mie derivatives.  

PubMed

Analytical expressions are obtained for the derivatives of Mie scattering coefficients with respect to the electrical radius of the spherical scattering particle, and to the relative permittivity and permeability of both the particle and the surrounding medium. Their corresponding approximate expressions are developed to avoid numerical overflow based on the logarithmic derivative of Riccati-Bessel functions. The analytical expressions have been verified by comparing their results with those calculated by analytical expressions developed by Mathematica. Compared with the numerical derivative, the analytical expressions and approximate expressions show a higher accuracy and are 2.0 and 2.8 times, respectively, faster in the case of a single magnetodielectric sphere. Generally, for spheres with an electrical radius in a large range, the approximate expressions can yield acceptable accuracy and computation time up to a high order. This work can be used in the design of nonmetallic metamaterials, and in the retrieval of aerosol properties from remote sensing data. An example calculation is given for the design of an optical, all-dielectric, mu-negative metamaterial consisting of a simple cubic array of tellurium nanoparticles. PMID:23852216

Li, Yang; Bowler, Nicola

2013-07-10

249

4-(N,N-dipropylamino)benzaldehyde inhibits the oxidation of all-trans retinal to all-trans retinoic acid by ALDH1A1, but not the differentiation of HL-60 promyelocytic leukemia cells exposed to all-trans retinal  

PubMed Central

Background The signal transduction pathways mediated by retinoic acid play a critical role in the regulation of cell growth and differentiation during embryogenesis and hematopoiesis as well as in a variety of tumor cell lines in culture. Following the reports that two members of the superfamily of aldehyde dehydrogenase (ALDH) enzymes, ALDH1A1 and ALDH1A2, were capable of catalyzing the oxidation of all-trans retinal to all-trans retinoic acid with submicromolar Km values, we initiated an investigation of the ability of 4-(N,N-dipropylamino)benzaldehyde (DPAB) to inhibit the oxidation of retinal by purified mouse and human ALDH1A1. Results Our results show that DPAB potently inhibits retinal oxidation, with IC50 values of 0.11 and 0.13 ?M for purified mouse and human ALDH1A1, respectively. Since the HL-60 human myeloid leukemic cell line has been used extensively to study the retinoic acid induced differentiation of HL-60 cells to granulocytes, and ALDH1A1 activity had previously been reported in HL-60 cells, we investigated the ability of DPAB to block differentiation of HL-60 promyelocytic leukemia cells exposed to retinal in culture. In HL-60 cells coincubated with 1 ?M retinal and 50 ?M DPAB for 144 hours, cell differentiation was inhibited only 30%. Furthermore, the NAD-dependent oxidation of propanal or retinal was less than 0.05 nmoles NADH formed/min-107 cells in spectrophotometric assays using HL-60 cell extracts. Conclusion Although ALDH1A1 may be the major catalytic activity for retinal oxidation in some retinoid-dependent mouse and Xenopus embryonic tissues and in adult human and mouse hematopoietic stem cells, another catalytic activity appears to synthesize the retinoic acid ligand necessary to stimulate the differentiation of HL-60 cells to end stage granulocytes.

Russo, James; Barnes, Annette; Berger, Katie; Desgrosellier, Jay; Henderson, Jennifer; Kanters, Ana; Merkov, Lubo

2002-01-01

250

Space Derived Air Monitor  

NASA Technical Reports Server (NTRS)

COPAMS, Commonwealth of Pennsylvania Air Monitoring System, derives from technology involved in building unmanned spacecraft. The Nimbus spacecraft carried experimental sensors to measure temperature, pressure, ozone, and water vapor, and instruments for studying solar radiation and telemetry. The process which relayed these findings to Earth formed the basis for COPAMS. The COPAMS system consists of data acquisition units which measure and record pollution level, and sense wind speed and direction, etc. The findings are relayed to a central station where the information is computerized. The system is automatic and supplemented by PAQSS, PA Air Quality Surveillance System.

1983-01-01

251

Deriving Darcy's Law  

NSDL National Science Digital Library

This exercise begins with a demonstration of fluid flow through porous sediment using a constant head permeameter, with the students conducting the experiment and collecting the data. The demo is followed by a Think-Pair-Share exercise in which the question is posed to the class: "What could we change in order to increase flow through the system?" The class then works through their brainstormed list of ideas, discussing each and evaluating whether it is correct or a misconception. The students derive Darcy's Law qualitatively, based upon the results of the Think-Pair-Share exercise and discussions.

Salvage, Karen

252

Fungicide pyrazole carboxamides derivates  

US Patent & Trademark Office Database

The present invention relates to pyrazole carboxamides derivatives of formula (1) wherein Y represents CR.sup.5 or N, T represents S or O, X1 and X2 represent a chlorine or a fluorine atom, and Z1 represents a substituted or non-substituted cyclopropyl; Their process of preparation, their use as fungicide, and/or anti-mycotoxin active agents, and/or insecticide, and/or nematicide, particularly in the form of fungicide compositions, and methods for the control of phytopathogenic fungi, notably of plants, using these compounds or compositions. ##STR00001##

2014-07-08

253

Sulphenamides and their derivatives  

NASA Astrophysics Data System (ADS)

Information has been presented systematically on the synthesis of sulphenamides and related compounds by reaction of sulphenyl chlorides and sulphur chlorides with amines and carboxylic acid amides; by reaction of chloramines with mercaptans; by transamination of N-acylsulphenamides; and by reaction of disulphides with amines. The following chemical reactions of sulphenamides have been examined: reaction with hydrogen halides; with acids and derivatives possessing coordinatively unsaturated atoms; and the addition of sulphenamides to the double bond of carbon disulphide, isocyanates, isothiocyanates and olefins. Data are given on the physical state of sulphenamides and on the region characteristic of the S-N bond vibrations. The bibliography includes 190 references.

Petrov, K. A.; Rudnev, G. V.; Sorokin, V. D.

1990-09-01

254

Connective tissue derived polypeptides  

US Patent & Trademark Office Database

The present invention relates to compositions comprising one or more connective tissue derived polypeptides having a molecular weight of less than 30,000 Da that are capable of tolerising individuals to antigenic components of cartilage and prevent the appearance of and/or treat symptoms of arthritis and other musculoskeletal degenerative conditions. The present invention provides methods for recovering polypeptides having a molecular weight of less than 30,000 Da from connective tissue and having anti-arthritic or anti-inflammatory activity. The present invention further relates to compositions comprising a polypeptide containing an NC4 domain of collagen type IX alpha 1 chain or fragment thereof, having a molecular weight of less than 30,000 Da, where the polypeptide is capable of tolerising individuals to antigenic components of cartilage, preventing the appearance of arthritic symptoms, and/or treating the symptoms of arthritis.

2011-04-05

255

Derivation of model topography  

NASA Technical Reports Server (NTRS)

The Fourth-Order model necessitates representation of the topography. The problem of the representation of the topography at grid points is addressed. The attempted was to derive an envelope topography. The TI is obtained by taking local mean plus one standard deviation at each grid point and sigma filtering it. The method was greatly influenced by large standard deviations at steep mountains. The O1 topography is the local mean. The S1 is obtained by Sigma filtering in both latitude and longitude the mean O1. The S2 is when the operation is applied twice and S3 thrice, the Q3 is the sigma filtered local mean of the upper third quantile of the source data.

Balgovind, R. C.

1985-01-01

256

Inositol derivatives: evolution and functions  

Microsoft Academic Search

Current research on inositols mainly focuses on myo-inositol (Ins) derivatives in eukaryotic cells, and in particular on the many roles of Ins phospholipids and polyphosphorylated Ins derivatives. However, inositols and their derivatives are more versatile than this — they have acquired diverse functions over the course of evolution. Given the central involvement of primordial bacteria and archaea in the emergence

Robert H. Michell

2008-01-01

257

Structure-affinity relationship studies of non-competitive NMDA receptor antagonists derived from dexoxadrol and etoxadrol.  

PubMed

The synthesis and NMDA receptor affinity of ring and side-chain homologues of etoxadrol and dexoxadrol are described. For the regioselective synthesis of etoxadrol homologues, the regioisomeric 4-azidobutanediols (+/-)-9 and (+/-)-14 were employed. A synthesis of the enantiomerically pure azidobutanediols (S)-, (R)-9 and (S)-, (R)-14 was developed and the homochiral building blocks were used for the synthesis of enantiomerically pure etoxadrol and dexoxadrol homologues. The affinity of the racemic and enantiomerically pure primary amines toward the phencyclidine binding site of the NMDA receptor was investigated in receptor binding studies with tritium labeled [3H]-(+)-MK-801 as radioligand. Benzaldehyde derivatives (+/-)-12a, (+/-)-13a, and (+/-)-16a bearing a proton at the acetalic position do not interact significantly with the NMDA receptor. An enantioselective NMDA receptor binding was observed for the trans-configured 2-(2-ethyl-2-phenyl-1,3-dioxolan-4-yl)ethanamine 13b, the (2-ethyl-2-phenyl-1,3-dioxan-4-yl)methanamine 16b, and the (2,2-diphenyl-1,3-dioxan-4-yl)methanamine 16c. The NMDA receptor affinity of these compounds resides almost exclusively in the (S)-configured enantiomers (2S,4S)-13b, (2S,4S)-16b, and (4S)-16c. The lowest Ki-value in this series was found for the (2S,4S)-configured 1,3-dioxolane (2S,4S)-13b (Ki = 69 nM), which is in the range of the Ki-value of the lead compounds etoxadrol and dexoxadrol, indicating that the 2-aminoethyl and the piperidin-2-yl substituents lead to similar NMDA receptor interactions. PMID:16169732

Aepkers, Marion; Wünsch, Bernhard

2005-12-15

258

Alcohol dehydrogenases from Scheffersomyces stipitis involved in the detoxification of aldehyde inhibitors derived from lignocellulosic biomass conversion.  

PubMed

Aldehyde inhibitors such as furfural and 5-hydroxymethylfurfural (HMF) are generated from biomass pretreatment. Scheffersomyces stipitis is able to reduce furfural and HMF to less toxic furanmethanol and furan-2,5-dimethanol; however, the enzymes involved in the reductive reaction still remain unknown. In this study, transcription responses of two known and five putative alcohol dehydrogenase genes from S. stipitis were analyzed under furfural and HMF stress conditions. All the seven alcohol dehydrogenase genes were also cloned and overexpressed for their activity analyses. Our results indicate that transcriptions of SsADH4 and SsADH6 were highly induced under furfural and HMF stress conditions, and the proteins encoded by them exhibited NADH- and/or NADPH-dependent activities for furfural and HMF reduction, respectively. For furfural reduction, NADH-dependent activity was also observed in SsAdh1p and NAD(P)H-dependent activities were also observed in SsAdh5p and SsAdh7p. For HMF reduction, NADPH-dependent activities were also observed in SsAdh5p and SsAdh7p. SsAdh4p displayed the highest NADPH-dependent specific activity and catalytic efficiency for reduction of both furfural and HMF among the seven alcohol dehydrogenases. Enzyme activities of all SsADH proteins were more stable under acidic condition. For most SsADH proteins, the optimum temperature for enzyme activities was 30 °C and more than 50 % enzyme activities remained at 60 °C. Reduction activities of formaldehyde, acetaldehyde, isovaleraldehyde, benzaldehyde, and phenylacetaldehyde were also observed in some SsADH proteins. Our results indicate that multiple alcohol dehydrogenases in S. stipitis are involved in the detoxification of aldehyde inhibitors derived from lignocellulosic biomass conversion. PMID:23912116

Ma, Menggen; Wang, Xu; Zhang, Xiaoping; Zhao, Xianxian

2013-09-01

259

DRS: Derivational Reasoning System  

NASA Technical Reports Server (NTRS)

The high reliability requirements for airborne systems requires fault-tolerant architectures to address failures in the presence of physical faults, and the elimination of design flaws during the specification and validation phase of the design cycle. Although much progress has been made in developing methods to address physical faults, design flaws remain a serious problem. Formal methods provides a mathematical basis for removing design flaws from digital systems. DRS (Derivational Reasoning System) is a formal design tool based on advanced research in mathematical modeling and formal synthesis. The system implements a basic design algebra for synthesizing digital circuit descriptions from high level functional specifications. DRS incorporates an executable specification language, a set of correctness preserving transformations, verification interface, and a logic synthesis interface, making it a powerful tool for realizing hardware from abstract specifications. DRS integrates recent advances in transformational reasoning, automated theorem proving and high-level CAD synthesis systems in order to provide enhanced reliability in designs with reduced time and cost.

Bose, Bhaskar

1995-01-01

260

The antioxidant activity of new coumarin derivatives.  

PubMed

The antioxidant activity of two synthesized coumarins namely, N-(4,7-dioxo-2- phenyl-1,3-oxazepin-3(2H,4H,7H)-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 5 and N-(4-oxo-2-phenylthiazolidin-3-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 6 were studied with the DPPH, hydrogen peroxide and nitric oxide radical methods and compared with the known antioxidant ascorbic acid. Compounds 5 and 6 were synthesized in a good yield from the addition reaction of maleic anhydride or mercaptoacetic acid to compound 4, namely N'-benzylidene-2-(2-oxo-2H-chromen-4-yloxy)acetohydrazide. Compound 4 was synthesized by the condensation of compound 3, namely 2-(2-oxo-2H-chromen-4-yloxy) acetohydrazide, with benzaldehyde. Compound 3, however, was synthesized from the addition of hydrazine to compound 2, namely ethyl 2-(2-oxo-2H-chromen-4-yloxy)acetate, which was synthesized from the reaction of ethyl bromoacetate with 4-hydroxycoumarin 1. Structures for the synthesized coumarins 2-6 are proposed on the basis of spectroscopic evidence. PMID:22016624

Kadhum, Abdul Amir H; Al-Amiery, Ahmed A; Musa, Ahmed Y; Mohamad, Abu Bakar

2011-01-01

261

The Antioxidant Activity of New Coumarin Derivatives  

PubMed Central

The antioxidant activity of two synthesized coumarins namely, N-(4,7-dioxo-2- phenyl-1,3-oxazepin-3(2H,4H,7H)-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 5 and N-(4-oxo-2-phenylthiazolidin-3-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 6 were studied with the DPPH, hydrogen peroxide and nitric oxide radical methods and compared with the known antioxidant ascorbic acid. Compounds 5 and 6 were synthesized in a good yield from the addition reaction of maleic anhydride or mercaptoacetic acid to compound 4, namely N?-benzylidene-2-(2-oxo-2H-chromen-4-yloxy)acetohydrazide. Compound 4 was synthesized by the condensation of compound 3, namely 2-(2-oxo-2H-chromen-4-yloxy) acetohydrazide, with benzaldehyde. Compound 3, however, was synthesized from the addition of hydrazine to compound 2, namely ethyl 2-(2-oxo-2H-chromen-4-yloxy)acetate, which was synthesized from the reaction of ethyl bromoacetate with 4-hydroxycoumarin 1. Structures for the synthesized coumarins 2–6 are proposed on the basis of spectroscopic evidence.

Kadhum, Abdul Amir H.; Al-Amiery, Ahmed A.; Musa, Ahmed Y.; Mohamad, Abu Bakar

2011-01-01

262

Synthesis of some pyridone derivatives.  

PubMed

Chlorination of 6-aryl-3-cyano-2-pyridone-4-carboxylic acid (1) afforded the corresponding acid chloride (2) and the 2-chloro derivative (3). Esterification of (2) gave the corresponding esters (4a; b). Hydrazinolysis of (4a) afforded the respective pyridazinone derivative (5). Treatment of 6-aryl-2-chloro-3-cyano-4-pyridine carboxylic acid (3) with acetyl hydrazine, gave the triazinopyridine derivative (6), while treatment of 3 with sodium azide in DMF afforded the tetrazinopyridine derivative (7). Treatment of the N-acetyl derivative (1b) with thiosemicarbazide and/or hydroxylamine hydrochloride, yielded the correspoding semicarbazone and oxine derivatives (8) and (10), respectively. The reaction of 6-aryl-3-cyano-1,2-dihydro-2-thioxo-4-pyridinecarboxylic acid (1c) with ethylchloro acetate and/or thiourea yielded the mercapto ester derivative (11) and the corresponding pyrido [2,3-d] pyrimidine thione derivative (12). Condensation reaction of (1d) with anthranilic acid, afforded the quinazolone derivative (11). The reactivity of 11 towards hydrazine hydrate was investigated. The structural assignment of the new derivatives were based on IR, 1H NMR and mass data. Some of the new compounds were screened, in vitro, for antimicrobial activity and the results were encouraging. PMID:11486604

Dawood, N T; Abdel-Gawad, S M; Soliman, F M

2001-01-01

263

Structural diversity in dinickel(II) complexes of thiosemicarbazones  

Microsoft Academic Search

2,6-Diformyl-p-cresol serves as a starting point for the generation of multidentate N\\/O\\/S chelating agents. Condensation with 4-(X-phenyl) thiosemicarbazide yields the pentadentate ligand having SNONS donor sequences, capable of holding two metal ions in close proximity. The ligands behave as mono\\/di\\/tri basic depending on the pH of the medium. Stereochemical diversity in the reaction product of such ligands with nickel(II) chloride

Anil D Naik; Satish M Annigeri; Umesh B Gangadharmath; Vidyanand K Revankar; Vinayak B Mahale

2002-01-01

264

2-Benzoyl-4-chloro-aniline thio-semi-carbazone  

PubMed Central

In the title compound, C14H13ClN4S, obtained from a reaction of 2-benzoyl-4-chloro­aniline with thio­semicarbazide in ethanol, the dihedral angle between the aromatic rings is 81.31?(13)°. In the crystal, the mol­ecules are linked by three N—H?S hydrogen bonds, forming centrosymmetric rings with set-graph motif R 2 2(8) and R 2 2(18), and resulting in the formation of a two-dimensional network lying parallel to (010).

Bandeira, Katlen C. T.; Bresolin, Leandro; Lehmann, Ueslei Z.; Zambiazi, Priscilla J.; de Oliveira, Adriano Bof

2014-01-01

265

Antifungal and Antioxidant Activities of Pyrrolidone Thiosemicarbazone Complexes  

PubMed Central

Metal complexes of (Z)-2-(pyrrolidin-2-ylidene)hydrazinecarbothioamide (L) with Cu(II), Co(II), and Ni(II) chlorides were tested against selected types of fungi and were found to have significant antifungal activities. The free-radical-scavenging ability of the metal complexes was determined by their interaction with the stable free radical 2,2??-diphenyl-1-picrylhydrazyl, and all the compounds showed encouraging antioxidant activities. DFT calculations of the Cu complex were performed using molecular structures with optimized geometries. Molecular orbital calculations provide a detailed description of the orbitals, including spatial characteristics, nodal patterns, and the contributions of individual atoms.

Al-Amiery, Ahmed A.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar

2012-01-01

266

2-Benzoyl-4-chloro-aniline thio-semi-carbazone.  

PubMed

In the title compound, C14H13ClN4S, obtained from a reaction of 2-benzoyl-4-chloro-aniline with thio-semicarbazide in ethanol, the dihedral angle between the aromatic rings is 81.31?(13)°. In the crystal, the mol-ecules are linked by three N-H?S hydrogen bonds, forming centrosymmetric rings with set-graph motif R 2 (2)(8) and R 2 (2)(18), and resulting in the formation of a two-dimensional network lying parallel to (010). PMID:24940260

Bandeira, Katlen C T; Bresolin, Leandro; Lehmann, Ueslei Z; Zambiazi, Priscilla J; de Oliveira, Adriano Bof

2014-06-01

267

Biomolecule derived nanostructured arrays  

NASA Astrophysics Data System (ADS)

During the last decade, intensive research have been reported on biomimetic approaches towards achieving mono-dispersed nanoparticles, and building self-assembled system out of those (organizing nanoparticles). However the development of this research avenue is being hindered by the limited knowledge and very few practical, efficient, cost-effective approaches for implementation of the bio-derived arrays into engineering practice. The objective of this work is to biomimeticaly form nanocomposite materials using a simple, rapid, inexpensive, scalable approach, which is general enough and not limited to colloidal particle self-assembly. Throughout the studies, we have developed a universally applicable process, which is to fabricate macro-biomolecular arrays on solid substrates based on the convective self-assembly of colloidal particles. We have demonstrated that protein (ferritin) and virus (phage) arrays were directly deposited onto solid substrates such as glass, silicon wafer, and gold substrate in closed or near closed-packed order. The arrays were further incorporated into a more robust silica matrix, in such that strengthens the thermal stability and provides porous accessibility. After treatment in controlled pyrolysis, the organic protein shell was removed, left mono-dispersed iron-oxide nanoparticles intact on the substrate or in the silica matrix. Both iron-oxide nanoparticles arrays with or without silica matrix have been further characterized to possess superferromagnetic properties at low temperature (15 K), same as that in bulk material. Initial work on protein patterning, through combining either lithography based top-down or bottom-up techniques with our novel deposition approach, was presented as well. Thin film deposition of mesoporous materials using convective self-assembly is another main part in this work. Both silica and carbon mesoporous thin films were successfully formed using the convective self-assembly horizontal-coating approach. We have shown that ultra thin mesoporous film (less than 100 nm) could be obtained through increasing the coating speed with the solution concentration remained same. Combining with lithographically patterned surface, the mesoporous thin films will be well suited for applications for bio-sensing, separations and etc. Studies were also carried out on the transport of fluid and electric current in fluidic channels with size in nanometer range; particular attention was paid on the effect of the electrolyte valence. At these dimensions new physical phenomena begin to occur because the electric double layers formed at the channel walls become comparable to the channel width and the overall wall surface to channel volume ratio increases. Numerical analysis predicts that the electrokinetic transport phenomena differ from multivalent ions to monovalent ions in the nanochannel when double layer overlap is large. This dependence affects the transport of current, fluid and dissolved analytes in a fluidic channel. The valence of the dissolved counterions determines the electric current and fluid flow in a nanochannel by shaping the electrostatic potential distribution. Our calculation shows that in absence of strong adsorption at the wall, divalent counterions lead to greater current and fluid flow than monovalent electrolyte for the same overall ionic strength. The results also indicate that control over the transport processes in fluidic nanochannels can be accomplished through properly selecting and combining electrolytes.

Yuan, Zhen

268

Optimal hedging of variance derivatives  

Microsoft Academic Search

We examine the optimal hedging of derivatives written on realised variance, focussing principally on variance swaps (VS) (but, en route, also considering skewness swaps), when the underlying stock price has discontinuous sample paths, i.e. jumps. In general, with jumps in the underlying, the market is incomplete and perfect hedging is not possible. We derive easily implementable formulae which give optimal

John Crosby

2012-01-01

269

Elementary derivation of Kepler's laws  

Microsoft Academic Search

A simple derivation of all three so-called Kepler laws is presented in which the orbits, bound and unbound, follow directly and immediately from conservation of energy and angular momentum. The intent is to make this crowning achievement of Newtonian mechanics easily accessible to students in introductory physics courses. The method is also extended to simplify the derivation of the Rutherford

Erich Vogt

1996-01-01

270

Derivatives Markets for Home Prices  

Microsoft Academic Search

The establishment recently of risk management vehicles for home prices is described. The potential value of such vehicles, once they become established, is seen in consideration of the inefficiency of the market for single family homes. Institutional changes that might derive from the establishment of these new markets are described. An important reason for these beginnings of real estate derivative

Robert J. Shiller

2008-01-01

271

Organoelementary Derivatives of Barenes (Carboranes-10)  

Microsoft Academic Search

CONTENTS I. Introduction 173 II. Magnesium and alkali-metal derivatives; syntheses based on them 174 III. Barenyl derivatives of boron 177 IV. Derivatives of Group IV elements 178 V. Derivatives of Group V elements (phosphorus, arsenic, antimony) 179 VI. Mercury derivatives 180 VII. Organometallic derivatives of dicarbaundecaborane 182 Bibtex entry for this abstract Preferred format for this abstract (see Preferences) Find

Vladimir I. Bregadze; O. Yu Okhlobystin

1968-01-01

272

Quinazoline derivatives: synthesis and bioactivities.  

PubMed

Owing to the significant biological activities, quinazoline derivatives have drawn more and more attention in the synthesis and bioactivities research. This review summarizes the recent advances in the synthesis and biological activities investigations of quinazoline derivatives. According to the main method the authors adopted in their research design, those synthetic methods were divided into five main classifications, including Aza-reaction, Microwave-assisted reaction, Metal-mediated reaction, Ultrasound-promoted reaction and Phase-transfer catalysis reaction. The biological activities of the synthesized quinazoline derivatives also are discussed. PMID:23731671

Wang, Dan; Gao, Feng

2013-01-01

273

Complex higher order derivative theories  

SciTech Connect

In this work is considered a complex scalar field theory with higher order derivative terms and interactions. A procedure is developed to quantize consistently this system avoiding the presence of negative norm states. In order to achieve this goal the original real scalar high order field theory is extended to a complex space attaching a complex total derivative to the theory. Next, by imposing reality conditions the complex theory is mapped to a pair of interacting real scalar field theories without the presence of higher derivative terms.

Margalli, Carlos A.; Vergara, J. David [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, Mexico 04510 DF (Mexico)

2012-08-24

274

MCR Synthesis of Praziquantel Derivatives  

PubMed Central

Schistosomiasis, a high volume neglected tropical disease affecting more than 200 million people worldwide, can only be effectively treated by the tetrahydroisoquinoline drug praziquantel (PZQ). Herein, we describe an efficient approach to access PZQ derivatives by the Ugi 4-component reaction followed by the Pictet-Spengler reaction in a two-step, one-pot procedure. 30 Novel PZQ derivatives are described based on the Ugi 4-component reaction and an X-ray structure of a novel derivative revealing different conformation compared with PZQ is discussed. Several analogues comparable in activity to the drug PZQ have been identified based on an in vitro Schistosoma mansoni worm viability assay.

Liu, Haixia; William, Samia; Herdtweck, Eberhardt; Botros, Sanaa; Domling, Alexander

2013-01-01

275

Elevation Derivatives for National Applications  

USGS Publications Warehouse

The Elevation Derivatives for National Applications (EDNA) project is a multi-agency effort to develop standard topographically derived layers for use in hydrologic and environmental modeling. The EDNA takes advantage of the seamless and filtered characteristics for the National Elevation Dataset (NED) to create a hydrologically conditioned Digital Elevation Model (DEM) useful for modeling applications. The goals of the project are to create a hydrologically conditioned DEM and systematically extract a set of standard derivatives that can be used to facilitate data integration with other U.S. Geological Survey (USGS) framework data sets such as the National Hydrography Dataset (NHD) and the Watershed Boundaries Dataset (WBD).

Geological Survey (U.S.)

2005-01-01

276

Quinazoline derivatives: synthesis and bioactivities  

PubMed Central

Owing to the significant biological activities, quinazoline derivatives have drawn more and more attention in the synthesis and bioactivities research. This review summarizes the recent advances in the synthesis and biological activities investigations of quinazoline derivatives. According to the main method the authors adopted in their research design, those synthetic methods were divided into five main classifications, including Aza-reaction, Microwave-assisted reaction, Metal-mediated reaction, Ultrasound-promoted reaction and Phase-transfer catalysis reaction. The biological activities of the synthesized quinazoline derivatives also are discussed.

2013-01-01

277

Biologically-Active Xanthine Derivatives.  

National Technical Information Service (NTIS)

Certain functionalized congeners of 1,3-dialkylxanthine exhibit high potency and selectivity as antagonists for A1- and A2-adenosine receptors and are suitable for attachment to probes, drug carriers, or solid supports. These derivatives are characterized...

K. A. Jacobson J. W. Daly K. L. Kirk

1984-01-01

278

Alkylsilyl derivatives for gas chromatography.  

PubMed

Alkylsilyl reagents are the most widely used reagents for the derivatization of polar compounds containing labile hydrogen atoms for gas chromatography. In this article the reagents and reaction conditions for the formation of trimethylsilyl, alkyldimethylsilyl (particularly t-butyldimethylsilyl), cyclic siliconides, haloalkyldimethylsilyl, and flophemesyl (pentafluorophenyldimethylsilyl) derivatives for a wide range of functional groups are reviewed. The importance of steric hindrance on reaction rates and completion, choice of reaction conditions, stability of derivatives, and options for selective detection are described. PMID:23465130

Poole, Colin F

2013-06-28

279

Nucleoside derivatives from the marine-derived fungus Aspergillusversicolor.  

PubMed

Four nucleoside derivatives (1-4) were isolated from the fungus Aspergillus versicolor derived from the gorgonian Dichotella gemmacea collected in the South China Sea. Their structures were elucidated by comprehensive spectroscopic method of NMR and MS analysis. All isolated metabolites were evaluated for their cytotoxicity, antibacterial activity and lethality towards brine shrimp Artemia salina. Compounds 1/2 exhibited selective antibacterial activity against Staphylococcus epidermidis with an MIC value of 12.5 ?M. It should be noted that 1 and 2, whose structures were listed in SciFinder Scholar, had no associated reference. This is the first report about their isolation, structure elucidation and biological activities. PMID:24670197

Chen, Min; Fu, Xiu-Mei; Kong, Chui-Jian; Wang, Chang-Yun

2014-01-01

280

Fractional Derivatives in Dengue Epidemics  

NASA Astrophysics Data System (ADS)

We introduce the use of fractional calculus, i.e., the use of integrals and derivatives of non-integer (arbitrary) order, in epidemiology. The proposed approach is illustrated with an outbreak of dengue disease, which is motivated by the first dengue epidemic ever recorded in the Cape Verde islands off the coast of west Africa, in 2009. Numerical simulations show that in some cases the fractional models fit better the reality when compared with the standard differential models. The classical results are obtained as particular cases by considering the order of the derivatives to take an integer value.

Pooseh, Shakoor; Rodrigues, Helena Sofia; Torres, Delfim F. M.

2011-09-01

281

Magnetic cellulose-derivative structures  

DOEpatents

Structures to serve as selective magnetic sorbents are formed by dissolving a cellulose derivative such as cellulose triacetate in a solvent containing magnetic particles. The resulting solution is sprayed as a fine mist into a chamber containing a liquid coagulant such as n-hexane in which the cellulose derivative is insoluble but in which the coagulant is soluble or miscible. On contact with the coagulant, the mist forms free-flowing porous magnetic microspheric structures. These structures act as containers for the ion-selective or organic-selective sorption agent of choice. Some sorption agents can be incorporated during the manufacture of the structure. 3 figs.

Walsh, M.A.; Morris, R.S.

1986-09-16

282

Empirically derived injury prevention rules.  

PubMed Central

This study describes a set of empirically derived safety rules that if followed, would have prevented the occurrence of minor injuries. Epidemiologists have criticized behavioral interventions as increasing "safe" behavior but failing to demonstrate a decrease in injury. The present study documents retrospectively the link between safe behavior and injury. It demonstrates that these empirically derived rules are very similar to rules for the prevention of serious injury. The study also shows that these rules are not widely accepted and implemented by parents. Suggestions for future research in this area are advanced.

Peterson, L; Schick, B

1993-01-01

283

Magnetic cellulose-derivative structures  

DOEpatents

Structures to serve as selective magnetic sorbents are formed by dissolving a cellulose derivative such as cellulose triacetate in a solvent containing magnetic particles. The resulting solution is sprayed as a fine mist into a chamber containing a liquid coagulant such as n-hexane in which the cellulose derivative is insoluble but in which the coagulant is soluble or miscible. On contact with the coagulant, the mist forms free-flowing porous magnetic microspheric structures. These structures act as containers for the ion-selective or organic-selective sorption agent of choice. Some sorbtion agents can be incorporated during the manufacture of the structure.

Walsh, Myles A. (Falmouth, MA); Morris, Robert S. (Fairhaven, MA)

1986-09-16

284

Synthesis and evaluation of novel 4-[(3H,3aH,6aH)-3-phenyl)-4,6-dioxo-2-phenyldihydro-2H-pyrrolo[3,4-d]isoxazol-5(3H,6H,6aH)-yl]benzoic acid derivatives as potent acetylcholinesterase inhibitors and anti-amnestic agents.  

PubMed

The present study was designed to synthesize and evaluate pyrrolo-isoxazole benzoic acid derivatives as potential acetylcholinesterase (AChE) inhibitors for the management of Alzheimer's disease. The synthesis of pyrrolo-isoxazole benzoic acid derivatives involved ring opening cyclization of p-aminobenzoic acid with maleic anhydride to yield maleanilic acid, which in turn afforded N-arylmaleimide via ring closed cyclization. Azomethine-N-oxides were obtained by condensation of N-arylhydroxylamine with differently substituted benzaldehydes followed by refluxing of N-arylmaleimide with differently substituted azomethine-N-oxides to pyrrolo-isoxazole benzoic acid derivatives as cis- and trans-stereoisomers. The synthesized compounds were evaluated in vitro for AChE inhibitory activity in rat brain homogenate with donepezil as standard AChE inhibitor. Thereafter, the most potent test compound was evaluated for in vitro butyrylcholinesterase inhibitory activity and in vivo memory evaluation in scopolamine (0.4mg/kg)-induced amnesia in mice by employing Morris water maze test. All pyrrolo-isoxazole benzoic acid derivatives demonstrated potent AChE inhibitory activity. Most of compounds exhibited similar activity to donepezil and four of them (7h, 7i, 8i, and 8h, IC(50)=19.1±1.9-17.5±1.5nM) displayed higher inhibitory activity as compared to donepezil (21.5±3.2nM) with compound 8ia (IC(50)=17.5±1.5nM) being the most active one. The test compound 8ia also ameliorated scopolamine-induced amnesia in mice in terms of restoration of time spent in target quadrant (TSTQ) and escape latency time (ELT). It may be concluded that pyrrolo-isoxazole benzoic acid derivatives may be employed as potential AChE inhibitors. PMID:22172310

Anand, Preet; Singh, Baldev

2012-01-01

285

40 CFR 721.1820 - Bisphenol derivative.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 2009-07-01 false Bisphenol derivative. 721.1820 Section 721...Chemical Substances § 721.1820 Bisphenol derivative. (a) Chemical substance...chemical substance identified generically as bisphenol derivative (PMN No....

2009-07-01

286

40 CFR 721.1820 - Bisphenol derivative.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Bisphenol derivative. 721.1820 Section 721...Chemical Substances § 721.1820 Bisphenol derivative. (a) Chemical substance...chemical substance identified generically as bisphenol derivative (PMN No....

2013-07-01

287

On the Higher Derivatives of Bellman'S Equation.  

National Technical Information Service (NTIS)

Bellman's equation is analysed by taking derivatives of all orders. It is found that unlike the second derivative which satisfies a nonlinear equation, the third and higher derivatives of the optimal value function satisfy linear differential equations al...

S. B. Gershwin

1969-01-01

288

Insider Trading in Credit Derivatives  

Microsoft Academic Search

Insider trading in the credit derivatives market has become a significant concern for regulators and participants. This paper attempts to quantify the problem. Using news reflected in the stock market as a benchmark for public information, we report evidence of significant incremental information revelation in the credit default swap (CDS) market, consistent with the occurrence of insider trading. We show

Viral V Acharya; Tim Johnson

2005-01-01

289

Microalgae derived biofuels and processes  

Microsoft Academic Search

only renewable biodiesel that can potentially completely displace liquid fuels derived from petroleum. The energy conversion reaction of microalgae can be classified into biochemical, thermochemical. Biochemical conversion can be further subdivided into alcoholic fermentation, anaerobic digestion and photobiological hydrogen production. Thermochemical conversion can be subdivided into gasification, pyrolysis and liquefaction. The productions of these processes include ethanol, methane, H2, Syngas,

Yibin Tian; Chunhu Li; Junjie Bian; Lijuan Feng

2011-01-01

290

Informational derivation of quantum theory  

SciTech Connect

We derive quantum theory from purely informational principles. Five elementary axioms - causality, perfect distinguishability, ideal compression, local distinguishability, and pure conditioning - define a broad class of theories of information processing that can be regarded as standard. One postulate - purification - singles out quantum theory within this class.

Chiribella, Giulio; D'Ariano, Giacomo Mauro; Perinotti, Paolo [Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Ontario, N2L 2Y5 (Canada); QUIT Group, Dipartimento di Fisica ''A. Volta'' and INFN Sezione di Pavia, via Bassi 6, I-27100 Pavia (Italy)

2011-07-15

291

Type-2 fuzzy fractional derivatives  

NASA Astrophysics Data System (ADS)

In this paper, we introduce two definitions of the differentiability of type-2 fuzzy number-valued functions of fractional order. The definitions are in the sense of Riemann-Liouville and Caputo derivative of order ? ? (0, 1), and based on type-2 Hukuhara difference and H2-differentiability. The existence and uniqueness of the solutions of type-2 fuzzy fractional differential equations (T2FFDEs) under Caputo type-2 fuzzy fractional derivative and the definition of Laplace transform of type-2 fuzzy number-valued functions are also given. Moreover, the approximate solution to T2FFDE by a Predictor-Evaluate-Corrector-Evaluate (PECE) method is presented. Finally, the approximate solutions of two examples of linear and nonlinear T2FFDEs are obtained using the PECE method, and some cases of T2FFDEs applications in some sciences are presented.

Mazandarani, Mehran; Najariyan, Marzieh

2014-07-01

292

Guggullipid derivatives: synthesis and applications.  

PubMed

Two guggullipid derivatives, Z-guggulsulfate [4,17(20)-pregnadiene-3-one-16beta-sulfate] sodium salt and Z-guggullaurate [4,17(20)-pregnadiene-3-one-16beta-laurate], have been synthesized and evaluated for liposomal drug delivery system. Its precursor, Z-guggulsterol [4,17(20)-pregnadiene-3-one-16beta-ol], is also synthesized in gram scale starting from guggulsterone using the novel combination of known reactions in fewer steps and with higher yield than previously reported synthesis. These new synthetic guggullipid derivatives were also used in the preparation of liposomes. This new class of lipid molecules will be a useful tool in the development of nanosomal or liposomal drug delivery system. PMID:20188717

Ahmad, Moghis U; Ali, Shoukath M; Ahmad, Ateeq; Sheikh, Saifuddin; Ahmad, Imran

2010-05-01

293

Stilbene derivatives from Gnetum cleistostachyum.  

PubMed

Three new stilbene derivatives, named gnetucleistol A (1), B (2) and C (3), together with four known compounds, gnetifolin A (4), p-hydroxycinnamic acid (5), piceatannol (6) and resveratrol (7), were isolated from Gnetum cleistostachyum C.Y. Cheng (Gnetaceae). Their structures were elucidated on the basis of spectroscopic evidence (EI-MS, UV, IR, NOE, 1H, 13C and 2D NMR). PMID:15621615

Yao, Chun-Suo; Lin, Mao; Liu, Xin; Wang, Ying-Hong

2005-04-01

294

Reid's recipe and derived categories  

Microsoft Academic Search

We prove two conjectures from Cautis and Logvinenko (2009) [CL09] which describe the geometrical McKay correspondence for a finite, abelian subgroup of SL3(C). We do it by studying the relation between the derived category mechanics of computing a certain Fourier–Mukai transform and a piece of toric combinatorics known as ‘Reid's recipe’, effectively providing a categorification of the latter.

Timothy Logvinenko

2010-01-01

295

Influence of lignocellulose-derived aromatic compounds on oxygen-limited growth and ethanolic fermentation by Saccharomyces cerevisiae  

Microsoft Academic Search

Phenolic compounds released and generated during hydrolysis inhibit fermentation of lignocellulose hydrolysates to ethanol\\u000a by Saccharomyces cerevisiae. A wide variety of aromatic compounds form from lignin, which is partially degraded during acid hydrolysis of the lignocellulosic\\u000a raw material. Aromatic compounds may also form as a result of sugar degradation and dare present in wood as extractives. The\\u000a influence of hydroxy-methoxy-benzaldehydes,

Simona Larsson; Alexis Quintana-Sáinz; Andres Reimann; Nils-Olof Nilvebrant; Leif J. Jönsson

2000-01-01

296

Synthesis, characterization and physiochemical information, along with antimicrobial studies of some metal complexes derived from an ON donor semicarbazone ligand  

Microsoft Academic Search

Eight new transition metal complexes of benzaldehyde-N(4)–phenylsemicarbazone have been synthesized and characterized by elemental analyses, molar conductance, electronic and infrared spectral studies. In all the complexes, the semicarbazone is coordinated as neutral bidentate ligand. 1H NMR spectrum of [Zn(HL)2(OAc)2] shows that there is no enolisation of the ligand in the complex. The magnetic susceptibility measurements indicate that Cr(III), Mn(II), Fe(III),

V. L. Siji; M. R. Sudarsana Kumar; S. Suma; M. R. Prathapachandra Kurup

2010-01-01

297

Cycloaddition of homophthalic anhydrides with aldehydes and ketones: a route to 3,4-dihydroisocoumarin-4-carboxylic acid derivatives  

Microsoft Academic Search

Homophthalic anhydride reacts with benzaldehyde in the presence of boron trifluoride-diethyl ether complex to give the cycloadduct 3-phenyl-3,4-dihydroisocoumarin-4-carboxylic acid in good to excellent yield. Under these conditions we did not observe the formation of Perkin-type products. The reaction can be extended to a wide variety of aldehydes and to some ketones in synthetically useful yields. Amides can be obtained in

Niefang Yu; Rébecca Poulain; André Tartar; Jean-Claude Gesquiere

1999-01-01

298

Binder enhanced refuse derived fuel  

DOEpatents

A refuse derived fuel (RDF) pellet having about 11% or more particulate calcium hydroxide which is utilized in a combustionable mixture. The pellets are used in a particulate fuel bring a mixture of 10% or more, on a heat equivalent basis, of the RDF pellet which contains calcium hydroxide as a binder, with 50% or more, on a heat equivalent basis, of a sulphur containing coal. Combustion of the mixture is effective to produce an effluent gas from the combustion zone having a reduced SO.sub.2 and polycyclic aromatic hydrocarbon content of effluent gas from similar combustion materials not containing the calcium hydroxide.

Daugherty, Kenneth E. (Lewisville, TX) [Lewisville, TX; Venables, Barney J. (Denton, TX) [Denton, TX; Ohlsson, Oscar O. (Naperville, IL) [Naperville, IL

1996-01-01

299

Iron and iron derived radicals  

SciTech Connect

We have discussed some reactions of iron and iron-derived oxygen radicals that may be important in the production or treatment of tissue injury. Our conclusions challenge, to some extent, the usual lines of thought in this field of research. Insofar as they are born out by subsequent developments, the lessons they teach are two: Think fastexclamation Think smallexclamation In other words, think of the many fast reactions that can rapidly alter the production and fate of highly reactive intermediates, and when considering the impact of competitive reactions on such species, think how they affect the microenvironment (on the molecular scale) ''seen'' by each reactive molecule. 21 refs., 3 figs., 1 tab.

Borg, D.C.; Schaich, K.M.

1987-04-01

300

Myeloid-derived suppressor cells  

PubMed Central

While conventional anticancer therapies, including surgical resection, radiotherapy, and/or chemotherapy, are relatively efficient at eliminating primary tumors, these treatment modalities are largely ineffective against metastases. At least in part, this reflects the rather inefficient delivery of conventional anticancer agents to metastatic lesions. We have recently demonstrated that myeloid-derived suppressor cells (MDSCs) can be used as cellular missiles to selectively deliver a radioisotope-coupled attenuated variant of Listeria monocytogenes to both primary and metastatic neoplastic lesions in mice with pancreatic cancer. This novel immunotherapeutic intervention robustly inhibited tumor growth while promoting a dramatic decrease in the number of metastases.

Chandra, Dinesh; Gravekamp, Claudia

2013-01-01

301

Shuttle derived unmanned launch vehicle  

NASA Astrophysics Data System (ADS)

An unmanned launch vehicle derived using existing Space Transportation System (STS) components was studied. The vehicle incorporates a standard STS external tank and solid rocket boosters, a new payload module and a recoverable propulsion/avionics module housing the high cost avionics and propulsion systems. The main propulsion system is a cluster of three STS space shuttle main engines compatible with the STS launch pad. The orbital maneuvering system utilizes components and the reaction control system incorporates modified STS primary and vernier thrusters. A solid rocket propulsion system made up of six motors having a two second burn time is incorporated for decelerating the recoverable propulsion/avionics module to a soft landing. The sidemount shuttle derived launch vehicle can carry 147,000 pounds to a 150 nautical mile circular orbit from the Eastern Test Range of 104,000 pounds from the Western Test Range. With Centaur G-prime the payload capability to geosynchronous earth orbit is 24,500 pounds. Performance with an optimized upper stage and a stretched external tank was also investigated.

Buell, D. N.; Tewell, J. R.

1985-04-01

302

Synthesis and characterization of novel polyimides derived from pyridine-bridged aromatic dianhydride and various diamines  

Microsoft Academic Search

A new kind of pyridine-bridged aromatic dianhydride monomer, 4-phenyl-2,6-bis[4-(3,4-dicarboxyphenoxy)phenyl]-pyridine dianhydride (PPDA), was successfully synthesized by modified Chichibabin reaction of benzaldehyde and substituted acetophenone, 4-(3,4-dicyanophenoxy)-acetophenone (DCAP), followed by acidic hydrolysis of the intermediate tetranitrile and cyclodehydration of the resulting tetraacid. The pyridine-bridged aromatic dianhydride was employed to synthesized a series of new pyridine-containing polyimides by polycondensation with various aromatic diamines in

Xiaolong Wang; Yanfeng Li; Shujiang Zhang; Tao Ma; Yu Shao; Xin Zhao

2006-01-01

303

Synthesis and spectroscopic study of aminals derived from 2-aminopyridine and 3-aminopyridine  

NASA Astrophysics Data System (ADS)

Treating 2-aminopyridine with pyridine-3-carboxaldehyde, pyridine-4-carboxaldehyde and benzaldehyde, and 3-aminopyridine with pyridine-4-carboxaldehyde leads to the formation of the corresponding aminal instead of the expected Schiff base. The IR and 1H NMR spectra of these compounds are described and discussed. Also, the X-ray data of the compound 3-pyridyl-N,N-di(2-pyridylamino)-methane is described and discussed. Infrared, 1H NMR and crystal data indicate that these aminals enjoy intermolecular hydrogen bonding. This effect is considered to contribute significantly to their unusual stability.

Iriepa, I.; Lorente, A.; Galvez, E.; Rubio, P.; Florencio, F.; Garcia-Blanco, S.

1986-03-01

304

40 CFR 721.10039 - Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic acid derivative...  

Code of Federal Regulations, 2011 CFR

...aminonaphthalenesulfonic acid derivative, ammonium salt (generic). 721.10039 Section 721...aminonaphthalenesulfonic acid derivative, ammonium salt (generic). (a) Chemical substance...aminonaphthalenesulfonic acid derivative, ammonium salt (PMN P-02-514) is subject to...

2011-07-01

305

Likelihood Ratio Derivative Estimators for Stochastic Systems.  

National Technical Information Service (NTIS)

This paper discusses the likelihood ratio derivative estimation techniques for stochastic systems. After a brief review of the basic concepts, likelihood ratio derivative estimators are presented for the following classes of stochastic processes: time hom...

P. W. Glynn

1989-01-01

306

12 CFR 403.4 - Derivative classification.  

Code of Federal Regulations, 2010 CFR

...the case of multiple source documents. (b) New Material. (1) New material that derives its classification from information...as assigned to the source information. (2) New material that derives its classification under prior...

2009-01-01

307

12 CFR 403.4 - Derivative classification.  

Code of Federal Regulations, 2010 CFR

...the case of multiple source documents. (b) New Material. (1) New material that derives its classification from information...as assigned to the source information. (2) New material that derives its classification under prior...

2010-01-01

308

Derivation of Equations for Variable Rainfall Infiltration.  

National Technical Information Service (NTIS)

Formulae were derived for prediction of ponding time and cumulative infiltration following ponding under a condition of variable and even intermittent rainfall. The derivations do not assume immediate saturation at the surface nor a piston displacement of...

H. J. Morel-Seytoux

1977-01-01

309

Derivative Sign Patterns in Two Dimensions  

ERIC Educational Resources Information Center

Given a function defined on a subset of the plane whose partial derivatives never change sign, the signs of the partial derivatives form a two-dimensional pattern. We explore what patterns are possible for various planar domains.

Schilling, Kenneth

2013-01-01

310

Evaluation of Derivatives of Gaussian Integrals.  

National Technical Information Service (NTIS)

We show that by a suitable change of variables, the derivatives of molecular integrals over Gaussian-type functions required for analytic energy derivatives can be evaluated with significantly less computational effort than current formulations. The reduc...

T. Helgaker P. R. Taylor

1992-01-01

311

Antibacterial activity of thioetherhydroxyethylsulfonamide derivatives.  

PubMed

Thioetherhydroxyethylsulfonamide derivatives were synthesized and evaluated for their in vitro antibacterial activity against Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853) and Staphylococcus aureus (ATCC 25923). Results have shown that compounds 8c and 9e display potent activity (MIC = 0.125 µg/mL) against E. coli when compared with the standard drug sulfamethoxazole (SMZ, MIC < 0.5 µg/mL) for this same strain. All the new compounds were fully identified and characterized by NMR ((1)H and (13)C) and X-ray crystallography (for compound 8c). This class of compounds can be considered as a good starting point for the development of new lead molecules in the fight against multi-drug bacterial resistance. PMID:24533504

Vellasco, Walcimar T; Guedes, Guilherme P; Facchinetti, Victor; Vasconcelos, Thatyana R A; Vaz, Maria G F; Cunico, Wilson; de Souza, Marcus V N; de Paula, Geraldo R; Fleming, Maria E C K; Gomes, Claudia R B

2014-05-01

312

[Coliphages inactivation using chitosan derivatives].  

PubMed

The effect of chitosan fragments with different degrees of polymerization and the chemical derivatives of chitosan differing in the number of amino groups and total molecule charge on phages T2, T4, and T7 was studied. The interaction of chitosan with bacteriophage particles inactivated them to the extent dependent on the chemical properties of chitosan and its concentration. Phage T2 was found to be most susceptible to inactivation by chitosan. The polycationic nature of chitosan plays an important role in the inactivation of phages. It is assumed that the abnormal rearrangement of the basal plate of phages, the loss of long tail fibers, and probably, modification of the receptor-recognizing phage proteins may be responsible for the inactivation of coliphages by chitosan. PMID:10776628

Kochkina, Z M; Surgucheva, N A; Chirkov, S N

2000-01-01

313

Using derivatives to hedge against the unexpected.  

PubMed

Derivatives--financial instruments with a rate of return derived from an underlying asset--have been used as investment instruments for decades. Many derivative products originally were created explicitly for the purpose of reducing financial risks and have become more widely used and more complex in recent years. Healthcare financial managers should have a basic understanding of derivatives as well as the ability to apply general guidelines for their appropriate use in healthcare financial management. PMID:10154438

Aderholt, J M; Rasmussen, R H

1996-02-01

314

Analytic Derivatives for Linear Rational Expectations Models  

Microsoft Academic Search

This paper sets out the analytic solution for the calculation of exact derivatives in linear rational expectations models with reference to the optimal simple rule problem. We argue that there are substantial computational advantages of using analytic derivatives and compare the likely computational costs of using approximate and exact derivatives when calculating optimal coefficients for simple feedback rules. A specific

Andrew P. Blake

2004-01-01

315

Improved Second Derivative Test for Relative Extrema  

ERIC Educational Resources Information Center

In this note, a modified Second Derivative Test is introduced for the relative extrema of a single variable function. This improved test overcomes the difficulty of the second derivative vanishing at the critical point, while in contrast the traditional test fails for this case. A proof for this improved Second Derivative Test is presented,…

Wu, Yan

2007-01-01

316

Additive (?, ?) -Jordan derivations on CSL algebras  

NASA Astrophysics Data System (ADS)

Let L be an CSL algebra. Where ?, ? are surjective homomorphisms on L. We say that an additive (linear) mapping ? of L into self is called an additive (linear)(?, ?) -derivation if ?(AB)= ?(A)?(B)+?(A)?(B) for any A, B?L. In this paper we show that an additive (?, ?) -Jordan derivation on a CSL-algebra is an additive (?, ?)-derivation.

Majeed, Asia

2010-11-01

317

Studies on antipeptic ulcer agents: the quantitative structure-activity relationship analysis of heterocyclic aldehyde N4-substituted phenyl (thio) semicarbazones.  

PubMed

Forty-five condensation products of furan-, pyrrole- and N-methyl pyrrole-alpha-carboaldehyde with N4-3- or N4-4-substituted phenyl semicarbazones and thiosemicarbazones were designed to optimize the antiulcer activity of a previously derived lead structure, formula II. Quantitative structure-activity relationships revealed that among the series of semicarbazones, increasing hydrophobicity and the introduction of electron-donating groups into the phenyl ring raise the antiulcer activity. Generally, semicarbazones are more active than the corresponding thiosemicarbazones. The wide gulf between the activity and toxicity of two derivatives (Compounds III and IV) necessitates further investigation of their pharmacological effects. PMID:1804380

Guo, Z; Yang, G; Chu, F; Zhang, S; Yu, Y

1991-06-01

318

Structural design utilizing updated, approximate sensitivity derivatives  

NASA Technical Reports Server (NTRS)

A method to improve the computational efficiency of structural optimization algorithms is investigated. In this method, the calculations of 'exact' sensitivity derivatives of constraint functions are performed only at selected iterations during the optimization process. The sensitivity derivatives utilized within other iterations are approximate derivatives which are calculated using an inexpensive derivative update formula. Optimization results are presented for an analytic optimization problem (i.e., one having simple polynomial expressions for the objective and constraint functions) and for two structural optimization problems. The structural optimization results indicate that up to a factor of three improvement in computation time is possible when using the updated sensitivity derivatives.

Scotti, Stephen J.

1993-01-01

319

Representations of partial derivatives in thermodynamics  

NSDL National Science Digital Library

One of the mathematical objects that students become familiar with in thermodynamics, often for the first time, is the partial derivative of a multivariable function. The symbolic representation of a partial derivative and related quantities present difficulties for students in both mathematical and physical contexts, most notably what it means to keep one or more variables fixed while taking the derivative with respect to a different variable. Material properties are themselves written as partial derivatives of various state functions (e.g., compressibility is a partial derivative of volume with respect to pressure). Research in courses at the University of Maine and Oregon State University yields findings related to the many ways that partial derivatives can be represented and interpreted in thermodynamics. Research has informed curricular development that elicits many of the difficulties using different representations (e.g., geometric) and different contexts (e.g., connecting partial derivatives to specific experiments).

Thompson, John R.; Manogue, Corinne A.; Roundy, David J.; Mountcastle, Donald B.

2012-05-15

320

Efficient Derivative-Free Optimization  

NASA Astrophysics Data System (ADS)

When optimizing the parameters affecting the evolution of a chaotic system, a peculiar challenge arises. The infinite-time average of the statistic of interest is only approximated by any finite-time simulation, with the truncation errors effectively decorrelated from one simulation to the next. Thus, the optimization surface is nonsmooth, and gradient-based optimization algorithms are ill suited. One of the most efficient derivative-free optimization algorithm available for such problems is the Surrogate Management Framework (SMF), which fits an interpolating function to the available data to identify regions of interest. The SMF is based on an underlying grid structure, with all function evaluations performed on this grid. Once discrete convergence is obtained, the grid is refined and the process repeated. In all previous SMF codes, Cartesian grids have been used. However, Cartesian grids are not nearly as uniform at packing or covering parameter space as various alternatives available from n-dimensional sphere packing theory. In the present talk, we show that, by leveraging such packings, the number of function evaluations required for convergence of the SMF algorithm is substantially reduced.

Belitz, Paul; Bewley, Thomas

2007-11-01

321

Animal-derived pharmaceutical proteins.  

PubMed

Livestock animals have made a significant contribution to human health and well-being throughout humankind's history. A significant contribution of farm animals to human health are the longstanding use of bovine and porcine for production of insulin (for treatment of diabetes), gelatin (for pharmaceutical and other purposes), as well as horse and sheep antibody against natural venoms, toxins, drugs and microbial peptides. Gelatin being the biggest animal protein consumed in human health, follows with antibodies fragments. The chronic problem of animal-derived therapeutics, especially those of high molecular weight, is the immunogenicity induction in addition to their biosafety. However, the invertebrates and lower vertebrates donate the human being a several crucial emergency saving life small-peptides or their analogs such as Refludan, Prialt, Exendin. Not only, but the farm animals are enormously using as models for novel surgical strategies, testing of biodegradable implants and sources of tissue replacements, such as skin and heart valves. Recently, they are being harnessing as bioreactor for production of biopharmaceutical related products through gene farming with efficiency far greater than any conventional microbial or cell-culture production systems. Only 16 transgenic cows would be covering the worldwide needs from human growth hormone. The transgenic, especially animal, technology would be solving a several biopharmaceutical products disadvantages, such as cost, biosafety, immunogenicity and the availability dimensions. PMID:19591041

Redwan, el-Rashdy M

2009-01-01

322

Clinical status of benzoporphyrin derivative  

NASA Astrophysics Data System (ADS)

Benzoporphyrin derivative monoacid ring A (BPD) is currently in Phase II clinical trials for the treatment of cutaneous malignancies (basal cell carcinoma and cutaneous metastases) and psoriasis. Results to date suggest that this photosensitizer has potential in both of these areas. Recently, a clinical trial with BPD was initiated for the treatment of age related macular degeneration, a neovascular condition in the eye which leads to blindness. BPD is a lipophilic photosensitizer which is rapidly taken up by activated cells and the vascular endothelium of neovasculature. The PDT effects seen with BPD appear to be a combination of vascular occlusion and direct killing of target cells. Since many diseases involve either activated cells and/or neovasculature, PDT with photosensitizer with characteristics like those of BPD, has applications far wider than oncology. A new area of interest involving photosensitizers is that of immune modulation. A number of photosensitizers have been shown to effect immune modulation in animal models of immune dysfunction including autoimmunity (rheumatoid arthritis, lupus), cutaneous hypersensitivity and allografts. BPD and PHOTOFRINR have both been shown to be effective in ameliorating arthritic symptoms in a number of animal models. The mechanisms by which immune modulation is affected in these studies still remains to be resolved.

Levy, Julia G.; Chan, Agnes H.; Strong, H. Andrew

1996-01-01

323

Satellite-Derived Management Zones  

NASA Technical Reports Server (NTRS)

The term "satellite-derived management zones" (SAMZ) denotes agricultural management zones that are subdivisions of large fields and that are derived from images of the fields acquired by instruments aboard Earth-orbiting satellites during approximately the past 15 years. "SAMZ" also denotes the methodology and the software that implements the methodology for creating such zones. The SAMZ approach is one of several products of continuing efforts to realize a concept of precision agriculture, which involves optimal variations in seeding, in application of chemicals, and in irrigation, plus decisions to farm or not to farm certain portions of fields, all in an effort to maximize profitability in view of spatial and temporal variations in the growth and health of crops, and in the chemical and physical conditions of soils. As used here, "management zone" signifies, more precisely, a subdivision of a field within which the crop-production behavior is regarded as homogeneous. From the perspective of precision agriculture, management zones are the smallest subdivisions between which the seeding, application of chemicals, and other management parameters are to be varied. In the SAMZ approach, the main sources of data are the archives of satellite imagery that have been collected over the years for diverse purposes. One of the main advantages afforded by the SAMZ approach is that the data in these archives can be reused for purposes of precision agriculture at low cost. De facto, these archives contain information on all sources of variability within a field, including weather, crop types, crop management, soil types, and water drainage patterns. The SAMZ methodology involves the establishment of a Web-based interface based on an algorithm that generates management zones automatically and quickly from archival satellite image data in response to requests from farmers. A farmer can make a request by either uploading data describing a field boundary to the Web site or else drawing the boundary on a reference image. Hence, a farmer can start to engage in precision farming shortly after gaining access to the Web site, without the need for incurring the high costs of conventional precision-agriculture data-collection practices that include collecting soil samples, mapping electrical conductivity of soil, and compiling multiyear crop-yield data. Given the boundary of a field, a SAMZ server computes the zones within the field in a three-stage process. In the first stage, a vector-valued image of the field is constructed by assembling, from the archives, the equivalent of a stack of the available images of the field (see figure). In the second stage, the vector-valued image is analyzed by use of a wavelet transform that detects spatial variations considered significant for precision farming while suppressing small-scale heterogeneities that are regarded as insignificant. In the third stage, a segmentation algorithm assembles the zones from smaller regions that have been identified in the wavelet analysis.

Lepoutre, Damien; Layrol, Laurent

2005-01-01

324

A newly synthesized thiazole derivative as a fluoride ion chemosensor: Naked-eye, spectroscopic, electrochemical and NMR studies.  

PubMed

2,3-Indoledione 3-thiosemicarbazone (TSCI) and a novel compound 3-(2-(4-(4-phenoxyphenyl)thiazol-2-yl)hydrazono)indolin-2-one (FTHI) were synthesized with high yield and characterized by spectroscopic techniques. The complexation behaviors of TSCI and FTHI for various anionic species (F(-), Cl(-), Br(-), I(-), NO2(-), NO3(-), BzO(-), HSO4(-), ClO4(-)) in CH3CN were investigated and compared by UV-vis spectroscopy, cyclic voltammetry and (1)H NMR titration techniques. FTHI showed high degree of selectivity for fluoride over other anions. This selectivity could be easily observed by the naked eye, indicating that FTHI is potential colorimetric sensor for fluoride anion. PMID:24691372

Sar?güney, Ahmet Burak; Saf, Ahmet Özgür; Co?kun, Ahmet

2014-07-15

325

A newly synthesized thiazole derivative as a fluoride ion chemosensor: Naked-eye, spectroscopic, electrochemical and NMR studies  

NASA Astrophysics Data System (ADS)

2,3-Indoledione 3-thiosemicarbazone (TSCI) and a novel compound 3-(2-(4-(4-phenoxyphenyl)thiazol-2-yl)hydrazono)indolin-2-one (FTHI) were synthesized with high yield and characterized by spectroscopic techniques. The complexation behaviors of TSCI and FTHI for various anionic species (F-, Cl-, Br-, I-, NO2-, NO3-, BzO-, HSO4-, ClO4-) in CH3CN were investigated and compared by UV-vis spectroscopy, cyclic voltammetry and 1H NMR titration techniques. FTHI showed high degree of selectivity for fluoride over other anions. This selectivity could be easily observed by the naked eye, indicating that FTHI is potential colorimetric sensor for fluoride anion.

Sar?güney, Ahmet Burak; Saf, Ahmet Özgür; Co?kun, Ahmet

2014-07-01

326

Consensus or Data Derived Anatomical Severity Scoring?  

PubMed Central

We aimed to compare the predictive accuracy of consensus derived and data derived injury severity scores when considered alone and in combination with age and physiological status. Analyses were based on 25,111 patients. The predictive validity of each severity score was evaluated in logistic regression models predicting in hospital mortality using measures of discrimination and calibration. Data derived scores had consistently better predictive accuracy than consensus derived scores in univariate models (p<0.0001) but very little difference between scores was observed in models including information on age and physiological status. Data derived scores provide more accurate mortality prediction than consensus derived scores when only anatomic injury severity is considered but offer little advantage if age and physiological status are taken into account.

Moore, Lynne; Lavoie, Andre; Le Sage, Natalie; Bergeron, Eric

2006-01-01

327

Primary ear fibroblast derivation from mice.  

PubMed

Mouse embryonic fibroblasts (MEFs) are commonly utilized as a primary cell culture model and have several advantages over other types of ex vivo-derived cells. However, the successful generation of MEFs is time consuming and requires a certain level of mouse expertise to successfully complete. Thus, primary ear-derived fibroblasts offer an acceptable alternative to MEFs. Fibroblasts derived from the pinna of adult mice are easily attainable with minimal skill, proliferate rapidly, and are easy to manipulate. Likewise, because they are derived from adult mice, other organs can be concurrently harvested for the isolation of additional types of primary cells. Similar to MEFs, ear fibroblasts are an excellent ex vivo model system to study mechanisms associated with virus infection and produce a diverse array of inflammatory mediators, such as cytokines and interferon. Here, we describe a highly versatile and simple method for the derivation, maintenance, and viral challenge of primary ear-derived fibroblasts from mice. PMID:23824888

Moore, Chris B; Allen, Irving C

2013-01-01

328

A subspace iteration for eigenvector derivatives  

NASA Technical Reports Server (NTRS)

An iterative procedure for calculating eigenvector derivatives has been developed based on the subspace iteration concept. The basic formulation is derived directly from the first variation of the resulting equations of subspace iteration for solving eigenvalue problems. Since the basic formulation conserves the convergence properties of the original subspace iteration for eigen-problems, an overrelaxation scheme similar to Bathe's approach is employed to accelerate the subspace iteration process for calculating eigenvector derivatives.

Ting, T.

1992-01-01

329

Anisotropic higher derivative gravity and inflationary universe  

NASA Astrophysics Data System (ADS)

Stability analysis of the Kantowski-Sachs type universe in pure higher derivative gravity theory is studied in detail. The nonredundant generalized Friedmann equation of the system is derived by introducing a reduced one-dimensional generalized Kantowski-Sachs type action. Existence and stability of inflationary solution in the presence of higher derivative terms are also studied in detail. Implications to the choice of physical theories are discussed in detail in this paper.

Kao, W. F.

2006-08-01

330

Adsorption and desorption of cellulose derivatives  

Microsoft Academic Search

Cellulose derivatives, in particular carboxymethyl cellulose (CMC) are used in many (industrial) applications. The aim of this work is to obtain insight into the adsorption mechanism of cellulose derivatives on solid-liquid interfaces.In chapter 1<\\/strong> of this thesis we discuss some applications of cellulose derivatives. Application of CMC in pelleting of iron ore and in papermaking and the role of adsorption

C. W. Hoogendam

1998-01-01

331

Cytotoxic activities of some novel benzhydrylpiperazine derivatives.  

PubMed

This study presents the synthesis of nineteen 1-(substitutedbenzoyl)-4-benzhydrylpiperazine and 1-[(substitutedphenyl)sulfonyl]-4-benzhydrylpiperazine derivatives. In vitro cytotoxic activities of the compounds were screened against hepatocellular (HUH-7), breast (MCF-7) and colorectal (HCT-116) cancer cell lines by sulphorhodamine B assay. Among the test compounds, benzamide derivatives had high cytotoxic activity whereas sulfonamide derivatives showed variable 50% growth inhibition (GI50). PMID:23447090

Gurdal, E E; Yarim, M; Durmaz, I; Cetin-Atalay, R

2013-03-01

332

Mantle derived economic sulfide mineralization?  

NASA Astrophysics Data System (ADS)

Sulfide ores of the unique Pt-Cu-Ni Noril'sk deposits are characterized by heavy sulfur isotopic composition (d34S = 6-18 ‰ ; Grinenko, 1985). These data are traditionally explained by the crustal contamination of the mantle melts by Devonian sedimentary rocks with anhydrites at certain depths or in a chamber of crystallization (Naldrett, 1992; Li et al., 2009). However, data on the distribution of major and trace elements and isotopic composition (their eNd, 87Sr/86Sr, d34S) in the contact zones of the intrusions with the host rocks are at variance with any significant in-situ contamination. Moreover , the mechanism of the "digestion" of this high-temperature material (Tm = 1430ºC) by the lower temperature magma (1250ºC) has never been analyzed and questioned. Our pioneering data on the sulfur radiogenic isotopes in the anhydrite are in conflict with the hypothesis that this mineral could serve as a sulfur source for the Noril'sk ores. The fact that the average composition of the intrusions is independent on the stratigraphic setting of these intrusions, which can be hosted by limestone, sandstone, and/or basalt, provides further support for the idea that no assimilation took place at the depths of the chambers in which the melts crystallized.The reason for the heavy sulfur isotopic composition of ores in the Noril'sk district is still uncertain. Last data obtained on the sulfur isotopic composition of basalts and ores from some intrusions in the Taimyr Peninsula likely provide a clue to this problem. The highest d34S values in rocks of all of the trap formations were detected in the Gudchikhinsky picrites (d34S = +8,7; Ripley et al., 2003) formed from a primitive mantle magma. They are geochemically similar to the rocks from the Dyumtaleysky Massif (d34S = 12.2; Krivolutskaya and Gongalsky, 2013) which crystallized from a primitive mantle-derived magma (with no Ta-Nb and Pb anomalies and high Gd/Yb ratio) too. This intrusion comprises economic important sulfide ores with geochemical and mineralogical characteristics similar to unique Noril'sk deposits - Talnakh, Okty'abr sky and Norilsk 1. The features of the Dyumtaleysky massif can be explained by its origin from an unusual sulfide-bearing mantle source that had sulfides through earlier crustal-mantle interaction. These data support that the mantle source of magmas in the Noril'sk district was enriched in the heavy sulfur isotope. It is the age difference that could be responsible for the unusual composition of the Noril'sk ores, because the mantle source in the Early Mesozoic was remarkably different from that in the Proterozoic one, when practically all Cu-Ni deposits worldwide were produced.

Krivolutskaya, Nadezda; Gongalskiy, Bronislav; Svirskaya, Natalia

2014-05-01

333

Formation of amino acid (L-leucine, L-phenylalanine) derived volatile flavour compounds by Moraxella phenylpyruvica and Staphylococcus xylosus in cured meat model systems.  

PubMed

A bacterial strain isolated from Danish immersion curing brine, Moraxella phenylpyruvica 0100, and a commercial meat starter culture, Staphylococcus xylosus DD34, were tested for their ability to form characteristic volatile compounds in minimal medium with the added amino acid L-leucine or L-phenylalanine under different environmental conditions (pH 5.5 and 6.0; 0 and 210 ppm nitrate; pre-incubation with and without agitation) and compared with respect to their ability to form volatile compounds in cured meat extracts and vacuum-packed cured meat cuts. The characteristic cured meat aroma precursors/compounds 3-methylbutanal and 3-methylbutanol were found to be formed in cured meat extracts and vacuum-packed cured meat cuts inoculated with M. phenylpyruvica. These volatiles are most probably formed by metabolic conversion of the amino acid L-leucine by M. phenylpyruvica, as they were also produced in minimal media with added L-leucine inoculated with this organism. The characteristic L-phenylalanine derived compound, benzaldehyde, formed by M. phenylpyruvica in minimal medium in the presence of nitrate (210 ppm), was not produced in any noticeable amount in cured meat extracts or vacuum-packed cured meat inoculated with M. phenylpyruvica. In contrast, benzacetaldehyde, which has been described as a possible metabolic product of the microbial conversion of L-phenylalanine, was found to be a characteristic volatile compound formed in cured meat extracts and vacuum-packed cured meat inoculated with M. phenylpyruvica, indicating an alternative metabolic pathway for L-phenylalanine by this organism in a cured meat environment. Even though S. xylosus was able to form volatile compounds characteristic of cured meats (3-methylbutanal, 3-methylbutanol) in minimal media with added L-leucine, this bacterial strain seemed not to be able to produce these characteristic volatiles in the studied cured meat systems. The present data imply that M. phenylpyruvica, in particular, is a potential meat starter for ensuring superior flavour development in cured meat. PMID:9706803

Møller, J K; Hinrichsen, L L; Andersen, H J

1998-06-30

334

Deriving the Area of a Circle.  

ERIC Educational Resources Information Center

Argues that the derivation of the area of a circle using integral calculus is invalid. Describes the derivation of the area of a circle when the formula is not known by inscribing and circumscribing the circle with regular polygons whose areas converge to the same number. (MDH)

Austin, Joe Dan

1992-01-01

335

Few Fractional Order Derivatives and Their Computations  

ERIC Educational Resources Information Center

This work presents an introductory development of fractional order derivatives and their computations. Historical development of fractional calculus is discussed. This paper presents how to obtain computational results of fractional order derivatives for some elementary functions. Computational results are illustrated in tabular and graphical…

Bhatta, D. D.

2007-01-01

336

Fruit and vegetable-derived compositions  

US Patent & Trademark Office Database

This invention provides fruit and vegetable-derived compositions comprising a fruit or vegetable derivative of inter alia, at least one Beta, Capsicum and Malus species, wherein the composition is at a pH in the range of about 3 to about 6.5. The invention further provides for process for the production of the same and uses thereof.

2014-03-18

337

Hematoporphyrin derivatives: an oligomeric composition study.  

PubMed

The oligomeric composition of HpD, Photofrin II and other hematoporphyrin derivatives useful for the diagnosis and therapy of tumors has been studied. Gel chromatographic procedures were used that excluded porphyrin aggregation. Photofrin and hematoporphyrin derivatives were shown to contain different quantities of monomer, dimer and other oligomeric porphyrins. PMID:2107292

Mironov, A F; Nizhnik, A N; Nockel, A Y

1990-01-01

338

Design and synthesis of new vancomycin derivatives.  

PubMed

A set of vancomycin derivatives with lipid chain attached via a glyceric acid linker was designed and synthesized. A concise synthesis towards these derivatives was developed and the IC50s of these new lipoglycopeptides were tested. Some of them showed very potent activity against both vancomycin sensitive and resistant strains. PMID:24751442

Gu, Wen; Chen, Bei; Ge, Min

2014-05-15

339

Derive Workshop Matrix Algebra and Linear Algebra.  

ERIC Educational Resources Information Center

This document presents the course content for a workshop that integrates the use of the computer algebra system Derive with topics in matrix and linear algebra. The first section is a guide to using Derive that provides information on how to write algebraic expressions, make graphs, save files, edit, define functions, differentiate expressions,…

Townsley Kulich, Lisa; Victor, Barbara

340

Meson spectroscopy with derivative quark sources  

Microsoft Academic Search

We present results for masses of light mesons obtained with the variational method using an enhanced basis of interpolating field operators with different quark smearings. The interpolators are constructed from Jacobi-smeared quarks of a Gaussian type as well as from derivative quark sources obtained by a covariant derivative acting on the Gaussian sources. For our analysis we use quenched gauge

Christof Gattringer; Leonid Ya. Glozman; C. B. Lang; Daniel Mohler; Sasa Prelovsek

2007-01-01

341

Understanding the Derivative through the Calculus Triangle  

ERIC Educational Resources Information Center

Typical treatments of the derivative do not clearly convey the idea that the derivative function represents the original function's rate of change. Revealing the relationship between a function and its rate-of-change function for static values of "x" does not facilitate productive ways of thinking about generating the rate-of-change function or…

Weber, Eric; Tallman, Michael; Byerley, Cameron; Thompson, Patrick W.

2012-01-01

342

Smoothing splines: Regression, derivatives and deconvolution  

NASA Technical Reports Server (NTRS)

The statistical properties of a cubic smoothing spline and its derivative are analyzed. It is shown that unless unnatural boundary conditions hold, the integrated squared bias is dominated by local effects near the boundary. Similar effects are shown to occur in the regularized solution of a translation-kernel intergral equation. These results are derived by developing a Fourier representation for a smoothing spline.

Rice, J.; Rosenblatt, M.

1982-01-01

343

ADIFOR --- Generating Derivative Codes from Fortran Programs  

Microsoft Academic Search

. The numerical methods employed in the solution of many scientific computing problems require the computationof derivatives of a function f : Rn!Rm. Both the accuracy and the computationalrequirements of the derivative computationare usually of critical importance for the robustness and speed of the numerical solution. ADIFOR (Automatic DifferentiationIn FORtran) is a source transformation tool that accepts Fortran 77 code

1991-01-01

344

Theory of Financial Risk and Derivative Pricing  

Microsoft Academic Search

Summarizing market data developments, some inspired by statistical physics, this book explains how to better predict the actual behavior of financial markets with respect to asset allocation, derivative pricing and hedging, and risk control. Risk control and derivative pricing are major concerns to financial institutions. The need for adequate statistical tools to measure and anticipate amplitude of potential moves of

Jean-Philippe Bouchaud; Marc Potters

2004-01-01

345

Lie derivations of certain CSL algebras  

Microsoft Academic Search

It is shown that each Lie derivation on a reflexive algebra, whose lattice is completely distributive and commutative, can\\u000a be uniquely decomposed into the sum of a derivation and a linear mapping with image in the center of the algebra.

Fangyan Lu

2006-01-01

346

Derived Categories and Zero-Brane Stability.  

National Technical Information Service (NTIS)

We define a particular class of topological field theories associated to open strings and prove the resulting D-branes and open strings form the bounded derived category of coherent sheaves. This derivation is a variant of some ideas proposed recently by ...

A. Lawrence

2001-01-01

347

Spanning and derivative-security valuationq  

Microsoft Academic Search

This article provides the economic foundations for valuing derivative securities. In particular, it establishes how the characteristic function (of the future uncertainty) is basis augmenting and spans the payo! universe of most, if not all, derivative assets. From the characteristic function of the state-price density, it is possible to analytically price options on any arbitrary transformation of the underlying uncertainty.

Gurdip Bakshi; Dilip Madan

1999-01-01

348

Novel Aflatoxin Derivatives and Protein Conjugates  

Microsoft Academic Search

Aflatoxins, a group of structurally related mycotoxins, are well known for their toxic and carcinogenic effects in humans and animals. Aflatoxin derivatives and protein conjugates are needed for diverse analytical applications. This work describes a reliable and fast synthesis of novel aflatoxin derivatives, purification by preparative HPLC and characterisation by ESI-MS and one- and two-dimensional NMR. Novel aflatoxin bovine serum

Christian Cervino; Dietmar Knopp; Michael G. Weller; Reinhard Niessner

2007-01-01

349

Drug laws and the 'derivative' problem.  

PubMed

The concept of a 'derivative' is used widely in chemistry, where its precise meaning depends on the circumstances. However, numerous examples of derivative also occur in domestic drugs legislation, some of which stem from the 1961 United Nations Single Convention on Narcotic Drugs. There is a commonly held view that only 'first-order' derivatives should be considered: substances that can be created from a parent structure in a single chemical reaction. In other words, 'derivatives of derivatives' are excluded. However, some substances related to ecgonine (e.g. 2-carbomethoxytropinone) are clearly convertible to cocaine, even though this may require more than one reaction step. It follows that 2-carbomethoxytropinone is a controlled drug, a situation that most chemists would regard as perverse. A more extreme example of the complexity of 'derivative' is shown by the conversion of thebaine to buprenorphine. Even though this requires six or more stages, the US Drug Enforcement Administration successfully argued in a 1986 case that for the purposes of the Controlled Substances Act, the number of steps required was irrelevant; buprenorphine was a derivative of thebaine. Because the term derivative is rarely defined in statutes, the legal status of some substances, such as 2-bromo-LSD, is uncertain. Although a number of definitions of derivative can be found in the chemical literature, no single definition is adequate to describe all situations where it occurs in legislation. Unless qualified, it is suggested that the term derivative should be avoided in any future legislation. Copyright © 2013 John Wiley & Sons, Ltd. PMID:23949903

King, Leslie A; Ujváry, István; Brandt, Simon D

2014-07-01

350

Aminoalkylcarbamyl Derivatives of Forskolin as Intermediates for the Synthesis of Useful Forskolin Derivatives.  

National Technical Information Service (NTIS)

The subject matter of the invention relates to aminoalkylcarbamates of forskolin and the uses of these compounds. Specifically, the aminoalkylcarbamates may be utilized as intermediates in the synthesis of forskolin derivatives. The final derivatives or a...

K. B. Seamon J. Robbins A. Laurenza

1990-01-01

351

An [11]cytochalasin derivative from the marine-derived fungus Xylaria sp. PSU-F100.  

PubMed

A new [11]cytochalasin derivative, xylarisin (1), was isolated from the marine-derived fungus Xylaria sp. PSU-F100 along with six known metabolites: three mellein derivatives (2-4), one pyrone derivative (5) and two carboxylic acids (6,7). The structure and stereochemistry of 1 were determined by NMR and X-ray diffraction analyses. All isolated compounds showed mild antibacterial activity against standard Staphylococcus aureus ATCC 25923 and methicillin-resistant strain. PMID:19952454

Rukachaisirikul, Vatcharin; Khamthong, Nanthaphong; Sukpondma, Yaowapa; Pakawatchai, Chaveng; Phongpaichit, Souwalak; Sakayaroj, Jariya; Kirtikara, Kanyawim

2009-12-01

352

CuI-Catalyzed C-N Bond Formation and Cleavage for the Synthesis of Benzimidazo[1,2-a]quinazoline Derivatives.  

PubMed

A copper(I)-catalyzed domino reaction of N-(2-benzimidazolyl)-2-aminobenzamide and 2-halogenated benzaldehyde has been studied. The procedure is based on a sequential CuI-catalyzed Ullmann reaction (C-N bond formation) and two bond cleavage reactions and provides an efficient strategy for the synthesis of benzimidazo[1,2-a]quinazolines catalyzed by CuI/l-proline. PMID:24885515

Li, Chao; Zhang, Wen-Ting; Wang, Xiang-Shan

2014-06-20

353

Theory of Financial Risk and Derivative Pricing  

NASA Astrophysics Data System (ADS)

Summarizing market data developments, some inspired by statistical physics, this book explains how to better predict the actual behavior of financial markets with respect to asset allocation, derivative pricing and hedging, and risk control. Risk control and derivative pricing are major concerns to financial institutions. The need for adequate statistical tools to measure and anticipate amplitude of potential moves of financial markets is clearly expressed, in particular for derivative markets. Classical theories, however, are based on assumptions leading to systematic (sometimes dramatic) underestimation of risks. First edition Hb (2000): 0-521-78232-5

Bouchaud, Jean-Philippe; Potters, Marc

2004-02-01

354

Synthesis of Sterically Hindered Polychlorinated Biphenyl Derivatives  

PubMed Central

A series of sterically hindered (methoxylated) polychlorinated biphenyl derivatives was synthesized using the Suzuki and the Ullmann coupling reaction. The Suzuki coupling with Pd(dba)2/2-dicyclohexylphosphino-2?,6?-dimethoxybiphenyl (DPDB) gave better yields (65–98%) compared to the classic Ullmann coupling reaction (20–38%). Despite the reactive catalyst system, no significant coupling with aromatic chlorine substituents was observed. Crystal structure analysis of four PCB derivatives revealed solid state dihedral angles ranging from 69.7° to 81.0°, which indicates that these highly ortho substituted PCB derivatives have some conformational flexibility.

Joshi, S. N.; Vyas, S. M.; Duffel, M. W.; Parkin, S.; Lehmler, H.-J.

2011-01-01

355

Synthesis of Hemigossypol and its Derivatives  

PubMed Central

Hemigossypol (3), a sesquiterpene natural product, was previously isolated from Gossypium barbadense and was shown to display improved anti-fungal activity compared to gossypol (1), the disesquiterpene dimer of hemigossypol (3). Gossypol exhibits multiple biological activities. In order to study whether hemigossypol and it derivatives retain the various bioactivities of gossypol, we developed a short and convenient synthetic scheme to synthesize hemigossypol. This is the first de novo synthesis of this natural product. In addition derivatives of hemigossypol with various 2,5-alkyl substituents were synthesized. Modification of the synthetic scheme also afforded the natural product hemigossylic lactone (4) and its 2,5-substituted derivatives.

Wei, Jun; Vander Jagt, David L.; Royer, Robert E.; Deck, Lorraine M.

2012-01-01

356

Water Soluble Derivatives of Frederimacycin A.  

National Technical Information Service (NTIS)

The present invention is related generally to fredericamycin A. More particularly, the present invention is related to new, water soluble, biologically active derivatives of fredericamycin A and a process for making the same.

R. Misra

1986-01-01

357

Derivatives of the Stochastic Growth Rate  

PubMed Central

We consider stochastic matrix models for population driven by random environments which form a Markov chain. The top Lyapunov exponent a, which describes the long-term growth rate, depends smoothly on the demographic parameters (represented as matrix entries) and on the parameters that define the stochastic matrix of the driving Markov chain. The derivatives of a — the “stochastic elasticities” — with respect to changes in the demographic parameters were derived by Tuljapurkar (1990). These results are here extended to a formula for the derivatives with respect to changes in the Markov chain driving the environments. We supplement these formulas with rigorous bounds on computational estimation errors, and with rigorous derivations of both the new and the old formulas.

Steinsaltz, David; Tuljapurkar, Shripad; Horvitz, Carol

2011-01-01

358

Deriving Linear Transformations in Three Dimensions  

Microsoft Academic Search

This article presents a general technique for solving elementary algebraic problems that arise in 3D geometry and then applies this method to derive explicit formulas for many of the linear transformations used in the standard 3D graphics pipeline.

Ron Goldman

2003-01-01

359

Catalytic combustion of coal-derived liquids  

NASA Technical Reports Server (NTRS)

A noble metal catalytic reactor was tested with three grades of SRC 2 coal derived liquids, naphtha, middle distillate, and a blend of three parts middle distillate to one part heavy distillate. A petroleum derived number 2 diesel fuel was also tested to provide a direct comparison. The catalytic reactor was tested at inlet temperatures from 600 to 800 K, reference velocities from 10 to 20 m/s, lean fuel air ratios, and a pressure of 3 x 10 to the 5th power Pa. Compared to the diesel, the naphtha gave slightly better combustion efficiency, the middle distillate was almost identical, and the middle heavy blend was slightly poorer. The coal derived liquid fuels contained from 0.58 to 0.95 percent nitrogen by weight. Conversion of fuel nitrogen to NOx was approximately 75 percent for all three grades of the coal derived liquids.

Bulzan, D. L.; Tacina, R. R.

1981-01-01

360

Diagrammatic Derivation of Coleman's Vanishing Cosmological Constant.  

National Technical Information Service (NTIS)

We present an alternative derivation of Coleman's expression for cosmological constant by summing over topologies of space-time in the wormhole dominance approximation. It is pointed out that the correlation between disconnected spaces, if any, vanishes b...

A. Hosoya

1988-01-01

361

Analysis and the Derivation of Valid Objectives  

ERIC Educational Resources Information Center

Author states that "to the extent that behavioral objectives are derived from an analysis of relatively broad objectives, they can serve as valid criteria which enable our students to avoid trivia." (Author)

Tiemann, Philip W.

1973-01-01

362

Formalization and Automatic Derivation of Code Generators.  

National Technical Information Service (NTIS)

This work is concerned with automatic derivation of code generators, which translate a parse-tree-like representation of programs into sequences of instructions for a computer defined by a machine description. In pursuing this goal, the following are pres...

R. G. G. Cattell

1978-01-01

363

Synthesis of Bisbenzil Isomers and Derivatives.  

National Technical Information Service (NTIS)

The goal of this investigation was to apply the modified benzoin condensation, used successfully in the synthesis of unsubstituted para-bis(phenylglyoxyloyl) benzene, to the preparation of substituted para-derivatives as well as to the production of selec...

K. L. Paciorek T. I. Ito R. H. Kratzer

1976-01-01

364

Derivation of OH concentrations from LIMS measurements  

NASA Astrophysics Data System (ADS)

Stratospheric concentrations of OH have been derived from LIMS measurements of minor constituents. Two methods have been used. Assuming that HNO3 and NO2 are in photochemical steady state, LIMS measurements of these species, with knowledge of appropriate rate constants and a calculation of the HNO3 photolysis rate, allow nearly global fields of OH to be derived. The derived profiles show satisfactory agreement with observations. As a check on the method, OH has also been derived by calculations of its sources and sinks using LIMS measurements of H2O. The two methods agree extremely well in low latitudes. At higher latitudes the agreement is less satisfactory. This is discussed in terms of the diurnal behavior of the species and the time constant of the HNO3/NO2 equilibrium.

Pyle, J. A.; Zavody, A. M.; Harries, J. E.; Moffat, P. H.

365

Nonadditive Probabilities and Derived Strengths of Preferences.  

National Technical Information Service (NTIS)

A method is introduced to derive strength of preference revelations on consequences from ordinal preferences on acts, based on Schmeidler's approach to decision making under uncertainty. Thus, a behavioral foundation is given for the maximization of subje...

P. Wakker

1987-01-01

366

Concise Derivation of the Rotational Partition Function.  

ERIC Educational Resources Information Center

Derived is the classical partition function for the rotation of a rigid asymmetric molecule, by a transformation of variables in the phase integral circumventing the cumbersome manipulation of the canonical prescription. (Author/GA)

Hynne, F.; Andersen, Knud

1979-01-01

367

Sums and Differences vs. Integrals and Derivatives.  

ERIC Educational Resources Information Center

Offers an approach to the understanding and to the teaching of the fundamental theorem of calculus. Stresses teaching the relation between a function and its derivative and the functions themselves. (YP)

Strang, Gilbert

1990-01-01

368

Methods of Therapy with Thrombin Derived Peptides.  

National Technical Information Service (NTIS)

The present invention relates to a method for promoting cardiac tissue repair comprising administering to the cardiac tissue a therapeutically effective amount of an angiogenic thrombin derivative peptide and/or inhibiting or reducing vascular occlusion o...

D. H. Carney

2004-01-01

369

Polypeptide Derivatives of Parathyroid Hormone (PTH).  

National Technical Information Service (NTIS)

Novel parathyroid hormone (PTH) polypeptide derivatives are disclosed, as are pharmaceutical compositions containing said polypeptides, and synthetic and recombinant methods for producing said polypeptides. Also disclosed are methods for treating mammalia...

H. Juppner H. M. Kronenberg J. T. Potts T. J. Gardella

2005-01-01

370

Reactions of Pentaborane (9) and Pentaborane Derivatives.  

National Technical Information Service (NTIS)

A number of pentaborane derivatives are prepared in their (11)B and (1)H nmr spectra recorded and correlated. Assessments of alternative preparative schemes are given. An extension of the apex to base rearrangement reaction to polyalkyl pentaboranes revea...

T. Onak G. B. Dunks I. W. Search J. R. Spielman

1966-01-01

371

A New Derivation of the Logistic Distribution.  

National Technical Information Service (NTIS)

Logistic distribution is widely used in describing biological, engineering, industrial, and various other types of data. In this paper it is shown that this distribution is a special case of a compound generalized extreme value distribution which is deriv...

S. D. Dubey

1969-01-01

372

New Derivation of the Rasch Model.  

National Technical Information Service (NTIS)

The Rasch model is usually derived from statistical requirements of estimation of its parameters. The principle of 'specific objectivity' or, equivalently, 'sample independence' requires that subject parameters can be estimated independent from the item p...

E. E. Roskam P. G. W. Jansen

1983-01-01

373

Biologically active amphiphilic derivatives of chitosan  

Microsoft Academic Search

Amphiphilic N-derivatives of chitosan containing C12 alkyl and carboxyl groups were obtained. It was shown that the compounds obtained have fungicidal activity and form intermolecular\\u000a associates in solutions.

E. A. Stepnova; V. E. Tikhonov; V. G. Babak; M. A. Krayukhina; K. K. Babievskii; I. A. Yamskov

2005-01-01

374

The Electromagnetic Activity of Porphin Derivatives.  

National Technical Information Service (NTIS)

The basic objective of the research was to explore the possibilities of using porphin derivatives as model compounds in a study of structure-property and structure-reactivity relationships. The large number of porphyrin structures available, their wide ra...

A. D. Adler

1967-01-01

375

Derivation of various NONMEM estimation methods  

Microsoft Academic Search

Various estimation methods and the lack of a systematic derivation of the core objective function implemented in NONMEM for\\u000a nonlinear mixed effect modeling has caused consistent confusion and inquiry among scientists who routinely use NONMEM for\\u000a data analysis. This paper provides a detailed derivation of the objective functions for the most commonly used estimation\\u000a methods in NONMEM, such as the

Yaning Wang

2007-01-01

376

Entropic-Gravity Derivation of MOND  

NASA Astrophysics Data System (ADS)

A heuristic entropic-gravity derivation has previously been given of the gravitational two-body force of modified Newtonian dynamics (MOND). Here, it is shown that another characteristic of MOND can also be recovered, namely, the external field effect (implying a violation of the Strong Equivalence Principle). In fact, the derivation gives precisely the modified Poisson equation which Bekenstein and Milgrom proposed as a consistent nonrelativistic theory of MOND.

Klinkhamer, F. R.

377

The lexical semantics of derived statives  

Microsoft Academic Search

This paper investigates the semantics of derived statives, deverbal adjectives that fail to entail there to have been a preceding\\u000a (temporal) event of the kind named by the verb they are derived from, e.g. darkened in a darkened portion of skin. Building on Gawron’s (The lexical semantics of extent verbs, San Diego State University, ms, 2009) recent observations regarding the

Andrew Koontz-Garboden

2010-01-01

378

Arbitrage Free Price Bounds for Property Derivatives  

Microsoft Academic Search

Market frictions inhibit the perfect replication of property derivatives, and define the property spread as a price measure\\u000a in the incomplete real estate market. We identify transaction costs, transaction time, and short sale constraints as the main\\u000a frictions in this market. Based on these frictions, we set up a framework of arbitrage free price bounds for property derivatives.\\u000a In turn,

Juerg M. Syz; Paolo Vanini

2011-01-01

379

Five new eremophilane derivatives from Ligularia sagitta  

Microsoft Academic Search

Ligulasagitins A–E (1–5), five new eremophilane-derived metabolites possibly formed via a Diels–Alder reaction in the biosynthetic process, were isolated from Ligularia sagitta Maxim. Among them 1 and 2 possess a novel C19 skeleton, 4 and 5 are two novel dimeric eremophilane type derivatives. Their structures were determined by extensive spectroscopic analysis and the structure of 2 was also confirmed by

Ping-Lin Li; Chun-Ming Wang; Zhan-Xin Zhang; Zhong-Jian Jia

2007-01-01

380

Hedging gas bills with weather derivatives  

Microsoft Academic Search

Natural gas company managers concerned with customer satisfaction attempt to minimize the occurrence of extreme bills. Previously,\\u000a only price fluctuations were addressed with derivative instruments; exchange-traded weather derivatives present a means of\\u000a hedging exposure to increases in quantity of gas demanded during colder than expected winter months. We model a natural gas\\u000a company’s ability to adjust for consumer sensitivity and

Karyl B. Leggio; Donald Lien

2002-01-01

381

Studies on peroxidized lipids. VI. Fluorescent products derived from the reaction of primary amines, malonaldehyde and monofunctional aldehydes  

Microsoft Academic Search

Monofunctional aldehydes such as acetaldehyde,n-propylaldehyde,n-butylaldehyde,n-hexylaldehyde,n-heptylaldehyde and benzaldehyde affected the reaction between primary amines and malonaldehyde. While the reaction of primary\\u000a amines and malonaldehyde at pH 7 produced fluorescent 4-methyl-1,4-dihydropyridine-3,5-dicarbaldehydesIa-f, the reaction of the primary amines, malonaldehyde and the aldehydes listed above gave fluorescent 4-substituted 1,4-dihydropyridine-3,5-dicarbaldehydesIIa-j. The primary amines used for this reaction included alkylamines, amino acids and alkanolamines. The optimal

Kiyomi Kikugawa; Yuko Ido; Atsushi Mikami

1984-01-01

382

Interaction of secondary amines with aromatic aldehydes-efficient method for synthesis of the functionalized heterocyclic amines  

Microsoft Academic Search

A method is proposed for the benzylation of secondary heterocyclic amines with functionalized derivatives of benzaldehyde\\u000a in the presence of formic acid under conditions close to amination according to the Leuckart-Wallach reaction.

Zh. V. Ignatovich; K. N. Gusak; T. V. Chernikhova; N. G. Kozlov; E. V. Koroleva

2007-01-01

383

Variation in genetic architecture of olfactory behaviour among wild-derived populations of Drosophila melanogaster.  

PubMed

Odour-guided behaviour is a quantitative trait determined by many genes that are sensitive to gene-environment interactions. Different natural populations are likely to experience different selection pressures on the genetic underpinnings of chemosensory behaviour. However, few studies have reported comparisons of the quantitative genetic basis of olfactory behaviour in geographically distinct populations. We generated isofemale lines of Drosophila melanogaster from six populations in Argentina and measured larval and adult responses to benzaldehyde. There was significant variation within populations for both larval and adult olfactory behaviour and a significant genotype x sex interaction (GSI) for adult olfactory behaviour. However, there is substantial variation in the contribution of GSI to the total phenotypic variance among populations. Estimates of evolvability are orders of magnitude higher for larvae than for adults. Our results suggest that the potential for evolutionary adaptation to the chemosensory environment is greater at the larval feeding stage than at the adult reproductive stage. PMID:18462315

Lavagnino, N J; Anholt, R R H; Fanara, J J

2008-07-01

384

Numerical derivative techniques for trajectory optimization  

NASA Technical Reports Server (NTRS)

The adoption of robust numerical optimization techniques in trajectory simulation programs has resulted in powerful design and analysis tools. These trajectory simulation/optimization programs are widely used, and a representative list includes the GTS system, the POST program, and newer collocation methods such as OTIS and FONPAC. All of these programs rely on optimization algorithms which require objective function and constraint gradient data during the iteration process. However, most trajectory optimization problems lack simple analytical expressions for these derivatives. In the general case a function evaluation involves integrating aerodynamic, propulsive, and gravity forces over multiple trajectory phases with complex control models. With the newer collocation methods, the integration is replaced by defect constraints and cubic approximations for the state. While analytic gradient expressions can sometimes be derived for trajectory optimization problems, the derivation is cumbersome, time consuming, and prone to mistakes. Fortunately, an alternate method exists for the gradient evaluation, namely finite difference approximations. In this paper some finite difference gradient techniques developed for use with the GTS system are presented. These techniques include methods for computing first and second partial derivatives of single and multiple sets of functions. A key feature of these methods is an error control mechanism which automatically adjusts the perturbation size to obtain accurate derivative values.

Hallman, Wayne P.

1990-01-01

385

Structure Activity Relationship of Brevenal Hydrazide Derivatives  

PubMed Central

Brevenal is a ladder frame polyether produced by the dinoflagellate Karenia brevis. This organism is also responsible for the production of the neurotoxic compounds known as brevetoxins. Ingestion or inhalation of the brevetoxins leads to adverse effects such as gastrointestinal maladies and bronchoconstriction. Brevenal shows antagonistic behavior to the brevetoxins and shows beneficial attributes when administered alone. For example, in an asthmatic sheep model, brevenal has been shown to increase tracheal mucosal velocity, an attribute which has led to its development as a potential treatment for Cystic Fibrosis. The mechanism of action of brevenal is poorly understood and the exact binding site has not been elucidated. In an attempt to further understand the mechanism of action of brevenal and potentially develop a second generation drug candidate, a series of brevenal derivatives were prepared through modification of the aldehyde moiety. These derivatives include aliphatic, aromatic and heteroaromatic hydrazide derivatives. The brevenal derivatives were tested using in vitro synaptosome binding assays to determine the ability of the compounds to displace brevetoxin and brevenal from their native receptors. A sheep inhalation model was used to determine if instillation of the brevenal derivatives resulted in bronchoconstriction. Only small modifications were tolerated, with larger moieties leading to loss of affinity for the brevenal receptor and bronchoconstriction in the sheep model.

Goodman, Allan; McCall, Jennifer R.; Jacocks, Henry M.; Thompson, Alysha; Baden, Daniel; Abraham, William M.; Bourdelais, Andrea

2014-01-01

386

Reactions of glycidyl derivatives with ambident nucleophiles; part 2: amino acid derivatives  

PubMed Central

A three-step procedure for the synthesis of multifunctionalized heterocycles from a pyroglutamic acid derivative, glycidyl components and anilines by nucleophilic substitution and cobalt catalysis is presented.

Dyker, Gerald; Thone, Andreas; Henkel, Gerald

2007-01-01

387

Increment of antimycobaterial activity on lichexanthone derivatives.  

PubMed

A new dihydropyranexanthone derived from the natural xanthone lichexanthone (1) was synthesised and, together with other 18 derivatives including ?-bromo and ?-aminoalkoxylxanthones (containing methyl, ethyl, propyl, tertbutylamino and piperidinyl moieties), were tested against Mycobacterium tuberculosis. Nine ?-aminoalkoxylxanthones showed good antimycobacterial activity, and their in vitro cytotoxicity was determined using VERO cells in order to calculate the selectivity index (SI). One of these nitrogenated xanthone derivatives showed very promising results, with MIC of 2.6 ?M and SI of 48. This MIC is comparable to values found in "first and second line" drugs commonly used to treat TB. In order to understand better about this compound, it was evaluated together with two other ones that showed good SI, against resistant clinical strains of M. tuberculosis to verify the existence of cross-resistance. A chemometrical approach was useful to establish a pattern of antitubercular activity among the group of ?-aminoalkoxylxanthones, according to some structural and chemical features. PMID:23106287

Micheletti, Ana Camila; Honda, Neli Kika; Pavan, Fernando R; Leite, Clarice Q F; Matos, Maria de Fatima Cepa; Perdomo, Renata Trentin; Bogo, Danielle; Alcantara, Glaucia Braz; Beatriz, Adilson

2013-11-01

388

Synthesis and properties of novel psoralen derivatives  

SciTech Connect

The authors have synthesized a set of new trimethylpsoralen derivatives that are characterized by a chain extending from the 4'-position of the furan ring and linked to this ring by an aminomethylene group. The nature of the side chain can be varied widely. In these derivatives, the chains contain either amino or ethylene oxide units for enhanced water solubility and allow the introduction of a thiol or amine group to nucleic acids. These compounds represent the first set of thiolated psoralen derivatives, and their usefulness is demonstrated in several nucleic acid cross-linking experiments. The reagents can be used to create both intraduplex reversible cross-links between the two single-strand partners in a DNA double helix and interduplex reversible cross-links between two DNA double helices.

Goldenberg, M.; Welsh, J.; Haas, R.; Rideout, D.C.; Cantor, C.R.

1988-09-06

389

Electrical derivative measurement of quantum cascade lasers  

NASA Astrophysics Data System (ADS)

The electrical derivative characteristics of quantum cascade lasers (QCLs) are investigated to test the QCL threshold, leakage current, and possibly explore carrier transport. QCL thresholds can be identified by searching for the slope peak of the first derivative of the I-V curves and can be further confirmed with its alignment to the peak of the second derivative of the I-V curves. Leakage current in QCLs with oxide-blocked ridge waveguides and buried heterostructure (BH) waveguides are studied and compared. The oxide-blocking structures provide the lowest leakage current although the capped-mesa-BH (CMBH) QCLs provide the toughest durability under highly stressful operations. The leakage current of CMBH QCLs are also compared at different temperatures.

Guo, Dingkai; Cheng, Liwei; Chen, Xing; Choa, Fow-Sen; Fan, Jenyu; Worchesky, Terry

2011-02-01

390

Conversion of tomato saponins to pregnane derivatives.  

PubMed

Here reports new conversions methods of tomato saponins, esculeoside A (1) and a mixture of esculeosides B-1 (2) and B-2 (3), (the latter two were obtained from tomato cans) into pregnane derivative (5) by an alkal treatment followed by acid treatment. Compound 1 or a mixture of 2 and 3 were each refluxed with 1?N KOH to afford a characteristic pyridine steroidal glycoside (4), which was then treated with 2?N HCl-MeOH to afford a pregnane derivative, 3?-hydroxy-5?-pregn-16-en-20-one (5). The results of the above two reactions indicated that tomato saponins are chemically closely related to pregnane hormones. We assume that the assimilated tomato saponins via the small intestine are metabolized into pregnane derivatives, demonstrating various bioactivities such as anti-cancer, anti-osteoporosis, and anti-menopausal disorder activities. PMID:24789931

Nohara, Toshihiro; Manabe, Hideyuki; Fujiwara, Yukio; Ikeda, Tsuyoshi; Ono, Masateru; Murakami, Kotaro; Nakano, Daisuke; Kinjo, Junei; Kajimoto, Tetsuya

2014-01-01

391

[Antiamyloid properties of fullerene C60 derivatives].  

PubMed

A comparative estimation of the ability of complexes of fullerene C60 with polyvinylpyrrolidone and fullerene C60 derivatives (the sodium salt of the polycarboxylic derivative of fullerene C60, sodium fullerenolate), has been carried out. The fullerenes destroyed amyloid fibrils of the Abeta(1-42) peptide of the brain and the muscle X-protein. A study of the effect of fullerenes on muscle actin showed that complexes of fullerene C60 with polyvinylpyrrolidone and sodium fullerenolate did not prevent the filament formation of actin, nor did they destroy its filaments in vitro. Conversely, sodium salt of the polycarboxylic derivative of fullerene C60 destroyed actin filaments and prevented their formation. It was concluded that sodium fullerenolate and complexes of fullerene C60 with polyvinylpyrrolidone are the most effective antiamyloid compounds among the fullerenes examined. PMID:22873064

Bobylev, A G; Shpagina, M D; Bobyleva, L G; Okuneva, A D; Piotrovski?, L B; Podlubnaia, Z A

2012-01-01

392

Geometric derivation of the quantum speed limit  

SciTech Connect

The Mandelstam-Tamm and Margolus-Levitin inequalities play an important role in the study of quantum-mechanical processes in nature since they provide general limits on the speed of dynamical evolution. However, to date there has been only one derivation of the Margolus-Levitin inequality. In this paper, alternative geometric derivations for both inequalities are obtained from the statistical distance between quantum states. The inequalities are shown to hold for unitary evolution of pure and mixed states, and a counterexample to the inequalities is given for evolution described by completely positive trace-preserving maps. The counterexample shows that there is no quantum speed limit for nonunitary evolution.

Jones, Philip J.; Kok, Pieter [Department of Physics and Astronomy, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom)

2010-08-15

393

Cyclodextrin derivatives as anti-infectives.  

PubMed

Cyclodextrin derivatives can be utilized as anti-infectives with pore-forming proteins as the targets. The highly efficient selection of potent inhibitors was achieved because per-substituted cyclodextrins have the same symmetry as the target pores. Inhibitors of several bacterial toxins produced by Bacillus anthracis, Staphylococcus aureus, Clostridium perfringens, Clostridium botulinum, and Clostridium difficile were identified from a library of ?200 CD derivatives. It was demonstrated that multi-targeted inhibitors can be found using this approach and could be utilized for the development of broad-spectrum drugs against various pathogens. PMID:24011515

Karginov, Vladimir A

2013-10-01

394

Special relativity derived from spacetime magma.  

PubMed

We present a derivation of relativistic spacetime largely untethered from specific physical considerations, in constrast to the many physically-based derivations that have appeared in the last few decades. The argument proceeds from the inherent magma (groupoid) existing on the union of spacetime frame components [Formula: see text] and Euclidean [Formula: see text] which is consistent with an "inversion symmetry" constraint from which the Minkowski norm results. In this context, the latter is also characterized as one member of a class of "inverse norms" which play major roles with respect to various unital [Formula: see text]-algebras more generally. PMID:24959889

Greensite, Fred

2014-01-01

395

Polyphenol derivatives - potential regulators of neutrophil activity  

PubMed Central

The study provides new information on the effect of natural polyphenols (derivatives of stilbene – resveratrol, pterostilbene, pinosylvin and piceatannol and derivatives of ferulic acid – curcumin, N-feruloylserotonin) on the activity of human neutrophils in influencing oxidative burst. All the polyphenols tested were found to reduce markedly the production of reactive oxygen species released by human neutrophils on extra-and intracellular levels as well as in cell free system. Moreover, pinosylvin, curcumin, N-feruloylserotonin and resveratrol decreased protein kinase C activity involved in neutrophil signalling and reactive oxygen species production. Our results suggest that due to their anti-neutrophil activity, the polyphenols tested might be attractive candidates in therapeutic development.

Perecko, Tomas; Nosal, Radomir; Harmatha, Juraj; Smidrkal, Jan; Jancinova, Viera

2012-01-01

396

Special Relativity Derived from Spacetime Magma  

PubMed Central

We present a derivation of relativistic spacetime largely untethered from specific physical considerations, in constrast to the many physically-based derivations that have appeared in the last few decades. The argument proceeds from the inherent magma (groupoid) existing on the union of spacetime frame components and Euclidean which is consistent with an “inversion symmetry” constraint from which the Minkowski norm results. In this context, the latter is also characterized as one member of a class of “inverse norms” which play major roles with respect to various unital -algebras more generally.

Greensite, Fred

2014-01-01

397

Terpenes from Marine-Derived Fungi  

PubMed Central

Terpenes from marine-derived fungi show a pronounced degree of structural diversity, and due to their interesting biological and pharmacological properties many of them have aroused interest from synthetic chemists and the pharmaceutical industry alike. The aim of this paper is to give an overview of the structural diversity of terpenes from marine-derived fungi, highlighting individual examples of chemical structures and placing them in a context of other terpenes of fungal origin. Wherever possible, information regarding the biological activity is presented.

Ebel, Rainer

2010-01-01

398

New coumarin derivatives as carbonic anhydrase inhibitors.  

PubMed

In the current study, a series of 4-chloromethyl-7-hydroxy-coumarin derivatives containing imidazolium, benzimidazolium, bisbenzimidazolium and quaternary ammonium salts were synthesized, characterized and the inhibition effects of the derivatives on human carbonic anhydrases (hCA I and hCA II) were investigated as in vitro. Structures of these coumarins were confirmed by FT-IR, (1)H NMR, (13)C NMR and LC-MS analyses. Structure activity relationship study showed that 3d (IC50: 79 ?M for hCA I and 88 ?M for hCA II) performed higher inhibitory activity than others. PMID:23656671

Karata?, Mert Olgun; Alici, Bülent; Cakir, Umit; Cetinkaya, Engin; Demir, Dudu; Ergün, Adem; Gençer, Nahit; Arslan, Oktay

2014-06-01

399

Synthesis and antifungal properties of papulacandin derivatives  

PubMed Central

Summary Derivatives of an antifungal agent that targets the ?-(1,3)-D-glucan synthase, papulacandin D, were synthesized and tested for activity. The papulacandin D structure contains a challenging benzannulated spiroketal unit, which is introduced in a palladium-catalyzed cross-coupling reaction of a glycal silanolate and an aryl iodide followed by an oxidative spiroketalization. Four different variants were made, differing in the nature of the acyl side chain with respect to the length, and in the number and stereochemistry of the double bonds. Moderate biological activity was observed for the derivatives with a side chain based on palmitic acid and linoleic acid.

van der Kaaden, Marjolein; Breukink, Eefjan

2012-01-01

400

Water-soluble derivatives of 1 -tetrahydrocannabinol.  

PubMed

Delta1-Tetrahydrocannabinol, which is resinous and insoluble in water and therefore difficult to study pharmacologically, can be converted to a watersoluble derivative without loss of its biological activity. This has been achieved by preparing esters bearing a nitrogen moiety with the use of carbodiimide as the condensing agent. The availability of such water-soluble derivatives will allow the evaluation of Delta1-tetrahydrocannabinol in self-administration studies in monkeys for its addiction liability potential in man. This technique of water solubilization is also applicable to other compounds of chemical and biological significance. PMID:5043146

Zitko, B A; Howes, J F; Razdan, R K; Dalzell, B C; Dalzell, H C; Sheehan, J C; Pars, H G; Dewey, W L; Harris, L S

1972-08-01

401

Structural studies of 4-aminoantipyrine derivatives  

NASA Astrophysics Data System (ADS)

Reaction of 4-aminoantipyrine with acetylacetone, ethyl acetoacetate, benzoyl isothiocyanate, phenyl isothiocyanate, maleic anhydride and methoxymethylene Meldrum's acid afforded a series of new antipyrine derivatives. The antibacterial activity of the synthesized compounds against Micrococcus luteus ATCC 9341, Staphilococcus aureus ATCC 29737, and Escherichia coli ATCC 8739 was evaluated and the minimal inhibitory concentration determined. Modest activity was found only to the maleamic acid obtained from the reaction of 4-aminoantipyrine and maleic anhydride. 1H NMR investigation of this maleamic acid showed that it is slowly converted to the corresponding toxic maleimide. The structures of three derivatives were determined by X-ray diffraction analysis.

Cunha, Silvio; Oliveira, Shana M.; Rodrigues, Manoel T.; Bastos, Rodrigo M.; Ferrari, Jailton; de Oliveira, Cecília M. A.; Kato, Lucília; Napolitano, Hamilton B.; Vencato, Ivo; Lariucci, Carlito

2005-10-01

402

Neutron stars in the derivative coupling model  

SciTech Connect

Properties of neutron stars derived from the hybrid derivative coupling model of nuclear field theory are studied. Generalized beta equilibrium with all baryon types to convergence is allowed. Hyperon couplings compatible with the inferred binding energy of the lambda hyperon in saturated nuclear matter predict a large hyperon population, with neutrons having a bare majority population in a 1.5{ital M}{sub {circle dot}} neutron star. Among the properties studied are the limits on rotation imposed by gravitation-radiation-reaction instabilities as moderated by viscosity. These instabilities place a lower limit on rotational periods of neutron and hybrid stars of about 1 ms.

Glendenning, N.K.; Weber, F. (Nuclear Science Division, Lawrence Berkeley Laboratory, University of California, One Cyclotron Road, Berkeley, California 94720 (United States)); Moszkowski, S.A. (University of California at Los Angeles, Department of Physics, Los Angeles , California 90024 (United States))

1992-02-01

403

Effects of guanidine derivatives on mitochondrial function  

PubMed Central

Long chain free fatty acids interfere with the inhibitory action of phenethylbiguanide and related compounds on mitochondrial respiration in vitro. This interference depends on binding of fatty acids to mitochondria and diminishes with decreasing chain length. Reversal of guanidine-derivative inhibition by fatty acids differs from that caused by dinitrophenol in that the effect of fatty acid is achieved without alteration in coupling or respiratory control. The binding of phenethylbiguanide to mitochondria is inhibited by both fatty acid and dinitrophenol. Serum albumin potentiates the inhibitory potency of guanidine derivatives, probably by removing endogenous mitochondrial free fatty acids.

Davidoff, Frank

1968-01-01

404

Elevation Derivatives for Mojave Desert Tortoise Habitat  

USGS Publications Warehouse

This report describes the methods used to derive various elevation-derivative grids that were inputted to the Mojave Desert Tortoise Habitat model (L. Gass and others, unpub. data). These grids, which capture information on surface roughness and topographic characteristics, are a subset of the environmental datasets evaluated for the tortoise habitat model. This habitat model is of major importance to the U.S. Fish and Wildlife Service, which is charged with management of this threatened population, including relocating displaced tortoises to areas identified as suitable habitat.

Wallace, Cynthia S. A.; Gass, Leila

2008-01-01

405

32 CFR 2400.14 - Use of derivative classification.  

Code of Federal Regulations, 2010 CFR

...OFFICE OF SCIENCE AND] [Subpart C - Derivative Classification] [Sec. 2400.14 - Use of derivative classification.] 32 NATIONAL DEFENSE...O. 12356; OFFICE OF SCIENCE AND Derivative Classification Sec. 2400.14...

2009-07-01

406

76 FR 43957 - Modifications of Certain Derivative Contracts  

Federal Register 2010, 2011, 2012, 2013

...1545-BK13 Modifications of Certain Derivative Contracts AGENCY: Internal Revenue...when there is an assignment of certain derivative contracts. The text of those regulations...that the transfer or assignment of a derivative contract in certain situations is...

2011-07-22

407

76 FR 43892 - Modifications of Certain Derivative Contracts  

Federal Register 2010, 2011, 2012, 2013

...1545-BK14 Modifications of Certain Derivative Contracts AGENCY: Internal Revenue...a transfer or assignment of certain derivative contracts does not result in an exchange...necessitate the movement of entire books of derivative contracts. In particular, there...

2011-07-22

408

21 CFR 173.135 - Catalase derived from Micrococcus lysodeikticus.  

Code of Federal Regulations, 2010 CFR

...2012-04-01 2012-04-01 false Catalase derived from Micrococcus lysodeikticus...Preparations and Microorganisms § 173.135 Catalase derived from Micrococcus lysodeikticus. Bacterial catalase derived from Micrococcus...

2012-04-01

409

Method of Introducing Hydroxyl Groups into Artemisinin and Its Derivatives.  

National Technical Information Service (NTIS)

The fungus Beauveria sulfurescens has been employed to introduce hydroxyl groups into artemisinin and derivatives of artemisinin, an antimalarial. Hydroxylated derivatives of artemisinin and derivatives of artemisinin produced thereby possess antimalarial...

H. Ziffer Y. Hu

1991-01-01

410

40 CFR 721.10172 - Alkylamide derivative (generic).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Alkylamide derivative (generic). 721.10172...Chemical Substances § 721.10172 Alkylamide derivative (generic). (a) Chemical...chemical substance identified generically as alkylamide derivative (PMN P-03-633)...

2010-07-01

411

21 CFR 173.135 - Catalase derived from Micrococcus lysodeikticus.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 false Catalase derived from Micrococcus lysodeikticus. 173.135 Section... § 173.135 Catalase derived from Micrococcus lysodeikticus. Bacterial catalase derived from Micrococcus lysodeikticus by a pure...

2009-04-01

412

21 CFR 173.135 - Catalase derived from Micrococcus lysodeikticus.  

Code of Federal Regulations, 2010 CFR

...2009-04-01 true Catalase derived from Micrococcus lysodeikticus. 173.135 Section... § 173.135 Catalase derived from Micrococcus lysodeikticus. Bacterial catalase derived from Micrococcus lysodeikticus by a pure...

2010-01-01

413

40 CFR 721.2025 - Substituted phenylimino carbamate derivative.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Substituted phenylimino carbamate derivative. 721.2025 Section 721...721.2025 Substituted phenylimino carbamate derivative. (a) Chemical substance...generically as a substituted phenylimino carbamate derivative (PMN P-91-487)...

2010-07-01

414

40 CFR 721.2025 - Substituted phenylimino carbamate derivative.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Substituted phenylimino carbamate derivative. 721.2025 Section 721...721.2025 Substituted phenylimino carbamate derivative. (a) Chemical substance...generically as a substituted phenylimino carbamate derivative (PMN P-91-487)...

2013-07-01

415

40 CFR 721.2025 - Substituted phenylimino carbamate derivative.  

Code of Federal Regulations, 2010 CFR

...2009-07-01 false Substituted phenylimino carbamate derivative. 721.2025 Section 721...721.2025 Substituted phenylimino carbamate derivative. (a) Chemical substance...generically as a substituted phenylimino carbamate derivative (PMN P-91-487)...

2009-07-01

416

40 CFR 721.6097 - Phosphoric acid derivative (generic name).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Phosphoric acid derivative (generic name...Chemical Substances § 721.6097 Phosphoric acid derivative (generic name...substance identified generically as a phosphoric acid derivative (PMN...

2010-07-01

417

Study on resist performance of chemically amplified molecular resist based on noria derivative and calixarene derivative  

NASA Astrophysics Data System (ADS)

Novel resist materials are required for lithographic processing with ionization radiation such as extreme ultraviolet (EUV) and electron beam (EB) exposure tool. In this study, we developed positive-tone chemically amplified molecular resists based on noria derivatives and calixarene derivatives and evaluated the lithographic performance using EUV and EB. We make clear that a small change in modification of noria resists can cause a significant change of sensitivity. Especially, it is useful for the improvement of resist sensitivities to use protecting groups such as 2-acetyloxy-2-methyladamantyl ester (AD) groups and ethoxy groups. Also, novel calixarene derivative such as pillar[5]arene protected by AD showed a semi-isolated pattern with the line width of 40 nm (pitch: 100nm). Noria derivatives and calixarene derivative resists were promising candidates because of high sensitivity, high resolution and etch durability similar to conventional resist such as ZEP 520A and UVIII.

Yamamoto, Hiroki; Kudo, Hiroto; Kozawa, Takahiro

2014-03-01

418

Mathematical Relationships Derived from Biodiesel Fuels  

Microsoft Academic Search

The objective of this study was to estimate mathematical relationships derived from biodiesel fuels from various vegetable oils by non-catalytic supercritical methanol and ethanol method. The vegetable oils are all extremely viscous with viscosities ranging from 10 to 20 times greater than petroleum diesel fuel. The aim of the transesterification process is to lower the viscosity of the oil. Methyl

A. Demirbas

2007-01-01

419

ES cell-derived neuroepithelial cell cultures.  

PubMed

ES cells have the potential to differentiate into cells from all germ layers, which makes them an attractive tool for the development of new therapies. In general, the differentiation of ES cells follows the concept to first generate immature progenitor cells, which then can be propagated and differentiated into mature cellular phenotypes. This also applies for ES cell-derived neurogenesis, in which the development of neural cells follows two major steps: First, the derivation and expansion of immature neuroepithelial precursors and second, their differentiation into mature neural cells. A common method to produce neural progenitors from ES cells is based on embryoid body (EB) formation, which reveals the differentiation of cells from all germ layers including neuroectoderm. An alternative and more efficient method to induce neuroepithelial cell development uses stromal cell-derived inducing activity (SDIA), which can be achieved by co-culturing ES cells with skull bone marrow-derived stromal cells. Both, EB formation and SDIA, reveal the development of rosette-like structures, which are thought to resemble neural tube- and/or neural crest-like progenitors. The neural precursors can be isolated, expanded and further differentiated into specific neurons and glia cells using defined culture conditions. Here, we describe the generation and isolation of such rosettes in co-culture experiments with the stromal cell line MS5 (2-5). PMID:18704173

Karki, Shreeya; Pruszak, Jan; Isacson, Ole; Sonntag, Kai C

2006-12-01

420

Dielectric spectra of natural cork and derivatives  

Microsoft Academic Search

Cork is a cellular biomaterial that has unique characteristics that make it suitable for many types of applications. Since it is also an electrical insulator, the study of its electrical and dielectric properties can lead to new interesting applications. The moisture present in cork and derivatives has a very important role on the dielectric properties. In this work a composite

M. C. Lança; M. Brandt; E. R. Neagu; C. J. Dias; J. N. Marat-Mendes

2010-01-01

421

Deriving a Pedagogy of Educational Foundations  

ERIC Educational Resources Information Center

This sixth and last paper in the series describes four elements believed to be crucial to a high quality pedagogy for educational foundations. These four elements are derived from a close reading of the previous papers. The work of Osguthorpe, Sanger, Haniford, and Mucher, four of the authors in this series, is cited as both a source for these…

Fenstermacher, Gary D.

2007-01-01

422

Simple Derivation of the Lindblad Equation  

ERIC Educational Resources Information Center

The Lindblad equation is an evolution equation for the density matrix in quantum theory. It is the general linear, Markovian, form which ensures that the density matrix is Hermitian, trace 1, positive and completely positive. Some elementary examples of the Lindblad equation are given. The derivation of the Lindblad equation presented here is…

Pearle, Philip

2012-01-01

423

Potentials of Arbitrary Forces with Fractional Derivatives  

NASA Astrophysics Data System (ADS)

The Laplace transform of fractional integrals and fractional derivatives is used to develop a general formula for determining the potentials of arbitrary forces: conservative and nonconservative in order to introduce dissipative effects (such as friction) into Lagrangian and Hamiltonian mechanics. The results are found to be in exact agreement with Riewe's results of special cases. Illustrative examples are given.

Rabei, Eqab M.; Alhalholy, Tareq S.; Rousan, Akram

424

Biotransformation of indole derivatives by mycelial cultures.  

PubMed

Biotransformation of tryptophan to tryptamine and 3-methyl-indole by Psilocybe coprophila was performed. On the other hand, Aspergillus niger was able to transform tryptophan to 5-hydroxy-tryptophan. P. coprophila biotransformed 5-hydroxy-tryptophan to 5-hydroxytryptamine. These results prove once more that fungi are good tools to establish hydroxyindole derivatives. PMID:18386493

Alarcón, Julio; Cid, Eliseo; Lillo, Luis; Céspedesa, Carlos; Aguila, Sergio; Alderete, Joel B

2008-01-01

425

High Resolution Sea Surface Temperature Field Derived.  

National Technical Information Service (NTIS)

A procedure for deriving high resolution sea surface temperature field from digital AVHRR/HRPT data is described. For the purpose of reducing the processing time, only the reflective threshold or near infrared channel is used for selecting data over clear...

S. Zhou W. Chen L. Zhang

1986-01-01

426

Waste-Wood-Derived Fillers for Plastics  

Microsoft Academic Search

Abstract Filled thermoplastic composites are stiffer, stronger, and more dimensionally stable than their unfilled counterparts Such thermoplastics are usually provided to the end - user as a precompounded, pelletized feedstock Typical reinforcing fillers are inorganic materials like talc or fiberglass, but materials derived from waste wood, such as wood flour and recycled paper fiber, are also effective as fillers The

Brent English; Craig M. Clemons; Nicole Stark; James P. Schneider

427

Pyrolysis kinetics of refuse-derived fuel  

Microsoft Academic Search

Refuse-derived fuel (RDF) was mechanically separated from municipal solid waste (MSW) in a 300 TPD (tons per day) waste pretreatment plant. Pyrolysis of the RDF produced approximately 28% of oils, and 30% of noncondensible hydrocarbon gases and 42% of solid residues at 773 K. Thermal gravimetric analysis (TGA) techniques were used in quantitative prediction of the RDF pyrolysis rate. The

Kuen-Song Lin; H. Paul Wang; S.-H Liu; Ni-Bin Chang; Y.-J Huang; H.-C Wang

1999-01-01

428

Synthesis of Sterically Rigid Cystamine Derivatives.  

National Technical Information Service (NTIS)

The possibility exists that the cystamine class of radiation protection drugs may be active only in certain conformations. If this should prove to be the case then cystamine derivatives that are rigidly held in the required conformation may be much more e...

R. M. Wilson D. N. Buchanan

1974-01-01

429

Synthesis of Sterically Rigid Cystamine Derivatives.  

National Technical Information Service (NTIS)

The possibility exists that the cystamine class of radiation protection drugs may be active only in certain conformations. If this should prove to be the cse then cystamine derivatives that are rigidly held in the required conformation may be much more ef...

D. N. Buchanan R. M. Wilson

1971-01-01

430

Antitumor activity of methylan polysaccharide derivatives.  

PubMed

Methylan polysaccharide derivatives were prepared by dialkylaminoalkylation and reductive amination followed by quaternization. Their antitumor activity was investigated and a relationship between structure and activity is suggested. For quaternized DEAE-methylan at only 75 mug ml(-1), tumor cell proliferation was suppressed by 58-84% in three cell lines tested in the order Colo < Hela < HepG2. PMID:20349111

Ramachandran, Priyadharshini; Jeya, Marimuthu; Moon, Hee-Jung; Lee, Kyoung-Mi; Kim, In-Won; Kim, Jung-Hoe; Lee, Jung-Kul

2010-07-01

431

Attenuation Correction In PET By Derived Projections  

Microsoft Academic Search

An improved approach to the attenuation correction necessary to produce quantitatively significant images with PET is presented. The algorithm retains the prac- tical properties of a measured attenuation conection, but reduces the variance in common applications. The basis of this technique is to reconstruct the attenua- tion image from the measured projections and then derive prs- jections from this image

D. C. Ficke; D. E. Beecher; G. R. Hoffman; M. M. Ter-Pogossian

1990-01-01

432

Intelligent Use of Model-Derived Products  

NSDL National Science Digital Library

Many NWP output products must undergo internal processing in order to be readily displayed and used. This module examines how such products are developed, their strengths and weaknesses, and their application in the forecast process. The module focuses on three primary groups of model-derived products: postprocessed products, statistical guidance products, and model assessment tools.

Spangler, Tim

1999-08-31

433

High speed point derivative microseismic detector  

DOEpatents

A high speed microseismic event detector constructed in accordance with the present invention uses a point derivative comb to quickly and accurately detect microseismic events. Compressional and shear waves impinging upon microseismic receiver stations disposed to collect waves are converted into digital data and analyzed using a point derivative comb including assurance of quiet periods prior to declaration of microseismic events. If a sufficient number of quiet periods have passed, the square of a two point derivative of the incoming digital signal is compared to a trip level threshold exceeding the determined noise level to declare a valid trial event. The squaring of the derivative emphasizes the differences between noise and signal, and the valid event is preferably declared when the trip threshold has been exceeded over a temporal comb width to realize a comb over a given time period. Once a trial event has been declared, the event is verified through a spatial comb, which applies the temporal event comb to additional stations. The detector according to the present invention quickly and accurately detects initial compressional waves indicative of a microseismic event which typically exceed the ambient cultural noise level by a small amount, and distinguishes the waves from subsequent larger amplitude shear waves. 9 figs.

Uhl, J.E.; Warpinski, N.R.; Whetten, E.B.

1998-06-30

434

Robust Derivation of Risk Reduction Strategies  

NASA Technical Reports Server (NTRS)

Effective risk reduction strategies can be derived mechanically given sufficient characterization of the risks present in the system and the effectiveness of available risk reduction techniques. In this paper, we address an important question: can we reliably expect mechanically derived risk reduction strategies to be better than fixed or hand-selected risk reduction strategies, given that the quantitative assessment of risks and risk reduction techniques upon which mechanical derivation is based is difficult and likely to be inaccurate? We consider this question relative to two methods for deriving effective risk reduction strategies: the strategic method defined by Kazman, Port et al [Port et al, 2005], and the Defect Detection and Prevention (DDP) tool [Feather & Cornford, 2003]. We performed a number of sensitivity experiments to evaluate how inaccurate knowledge of risk and risk reduction techniques affect the performance of the strategies computed by the Strategic Method compared to a variety of alternative strategies. The experimental results indicate that strategies computed by the Strategic Method were significantly more effective than the alternative risk reduction strategies, even when knowledge of risk and risk reduction techniques was very inaccurate. The robustness of the Strategic Method suggests that its use should be considered in a wide range of projects.

Richardson, Julian; Port, Daniel; Feather, Martin

2007-01-01

435

Sol-Gel Derived Hafnia Coatings  

NASA Technical Reports Server (NTRS)

Sol-gel derived hafnia coatings are being developed to provide an oxidation protection layer on ultra-high temperature ceramics for potential use in turbine engines (ultra-efficient engine technology being developed by NASA). Coatings using hafnia sol hafnia filler particles will be discussed along with sol synthesis and characterization.

Feldman, Jay D.; Stackpoole, Mairead; Blum, Yigal; Sacks, Michael; Ellerby, Don; Johnson, Sylvia M.; Venkatapathy, Ethiras (Technical Monitor)

2002-01-01

436

78 FR 76787 - Position Limits for Derivatives  

Federal Register 2010, 2011, 2012, 2013

...37, 38, 140 and 150 RIN 3038-AD99 Position Limits for Derivatives Correction In proposed rule document 2013-27200 appearing...100 3,100 .............. CME Feeder Cattle (FC).. 2011 44,611 43,730 3,000 3,000 3,000 2012...

2013-12-19

437

Derivation of the Ideal Gas Law  

ERIC Educational Resources Information Center

Undergraduate and graduate physics and chemistry books usually state that combining the gas laws results in the ideal gas law. Leaving the derivation to the students implies that this should be a simple task, most likely a substitution. Boyle's law, Charles's law, and the Avogadro's principle are given under certain conditions; therefore, direct…

Laugier, Alexander; Garai, Jozsef

2007-01-01

438

Optical limiting properties of [60]fullerene derivatives  

SciTech Connect

Materials such as organic dyes that are strong nonlinear absorbers are being investigated as optical limiting materials for potential applications in the protection of sensors and human eyes from laser radiations. The optical limiting properties of methano[60]fullerene and pyrrolidino[60]fullerene derivatives were investigated. 27 refs., 8 figs., 1 tab.

Sun, Ya-Ping; Riggs, J.E.; Liu, Bing [Clemson Univ., SC (United States)] [Clemson Univ., SC (United States)

1997-05-01

439

Techniques for automatic video content derivation  

Microsoft Academic Search

In this paper, we focus on the use of three different techniques that support automatic derivation of video content from raw video data, namely, a spatio-temporal rule-based method, hidden Markov models, and dynamic Bayesian networks. These techniques are validated in the particular domain of tennis and Formula 1 race videos. We present the experimental results for the detection of events

Milan Petkovic; Vojkan Mihajlovic; Willem Jonker

2003-01-01

440

Convenient syntheses of isomaltose derivatives from amygdalin  

Microsoft Academic Search

The isomaltose trichloroacetimidate 7 was synthesized in five steps from d-amygdalin. The key step in this series of reactions was the acid catalyzed rearrangement of the inter-glycosydic bond to give the thermodynamically more stable ?-anomer. The reaction was also applied to different di-, tri-, and tetrasaccharide derivatives of amygdalin giving the corresponding rearrangement products.

Martin Chwalek; Karen Plé

2004-01-01

441

Inhibition of topoisomerase I by naphthoquinone derivatives  

Microsoft Academic Search

Alkannin and shikonin are naturally occurring naphthoquinones. We have tested several derivatives of the title compounds and we have found that naphthoquinones bearing at least one phenolic hydroxyl group are potent inhibitors of topoisomerase I. The ability of the tested compounds to complex Zn++ parallels with a few exceptions their topoisomerase I inhibition properties while their intercalation and redox properties

Zoi F. Plyta; Tianhu Li; Vassilios P. Papageorgiou; Antonios S. Mellidis; Andreana N. Assimopoulou; Emmanuel N. Pitsinos; Elias A. Couladouros

1998-01-01

442

Financial Derivatives Market for Grid Computing  

Microsoft Academic Search

This Master thesis studies the feasibility and properties of a financial derivatives market on Grid computing, a service for sharing computing resources over a network such as the Internet. For the European Organization for Nuclear Research (CERN) to perform research with the world's largest and most complex machine, the Large Hadron Collider (LHC), Grid computing was developed to handle the

David Aubert; Arnstein Seljeflot Solli; Snorre Lindset; Henning Huuse

2007-01-01

443

An Overview of the Literature about Derivatives  

Microsoft Academic Search

A derivative is defined by the BIS (1995) as “a contract whose value depends on the price of underlying assets, but which does not require any investment of principal in those assets. As a contract between two counterparts to exchange payments based on underlying prices or yields, any transfer of ownership of the underlying asset and cash flows becomes unnecessary”.

Chiara Oldani

2005-01-01

444

Approximate methods for derivation of covariance data  

SciTech Connect

Several approaches for the derivation of covariance information for evaluated nuclear data files (EFF2 and ENDF/B-VI) have been developed and used at IRK and ORNL respectively. Considerations, governing the choice of a distinct method depending on the quantity and quality of available data are presented, advantages/disadvantages are discussed and examples of results are given.

Tagesen, S. [Vienna Univ. (Austria). Inst. fuer Radiumforschung und Kernphysik; Larson, D.C. [Oak Ridge National Lab., TN (United States)

1992-12-31

445

Embryogenesis in callus derived from rice microspores  

Microsoft Academic Search

Differentiating calli derived from rice (Oryza sativa L.) microspores were examined histologically. Shoot and root meristems were observed to be arising by both organogenesis as well as embryogenesis. Embryoid attachment to callus (as well as other embryoids) was at the scutellum adjacent to the mesocotyl and radicle. These observations could be interpreted as an indication of the totipotent plasticity of

A. D. Genovesi; C. W. Magill

1982-01-01

446

Tormentic acid derivatives: synthesis and apoptotic activity.  

PubMed

Several derivatives of tormentic acid have been prepared and tested for their antitumor activity. The dichloroacetate 14 is an excellent antitumor active agent acting by an apoptose inducing pathway as demonstrated by OA/PI staining, DNA laddering experiments as well as by an annexin V binding assay. PMID:22995818

Csuk, René; Siewert, Bianka; Dressel, Christian; Schäfer, Renate

2012-10-01

447

Combustion Studies of Coal Derived Fuels.  

National Technical Information Service (NTIS)

Combustion studies were conducted to evaluate the suitability of using a coal-derived aviation fuel as a candidate JP-900 i.e. a aviation fuel having maximum temperature capability of 482C (900F). Specific progress made for the four tasks constituting Del...

R. J. Santoro

2000-01-01

448

UNDERSTANDING, DERIVING, AND COMPUTING BUFFER CAPACITY  

EPA Science Inventory

Derivation and systematic calculation of buffer capacity is a topic that seems often to be neglected in chemistry courses and given minimal treatment in most texts. However, buffer capacity is very important in the chemistry of natural waters and potable water. It affects corro...

449

High speed point derivative microseismic detector  

DOEpatents

A high speed microseismic event detector constructed in accordance with the present invention uses a point derivative comb to quickly and accurately detect microseismic events. Compressional and shear waves impinging upon microseismic receiver stations disposed to collect waves are converted into digital data and analyzed using a point derivative comb including assurance of quiet periods prior to declaration of microseismic events. If a sufficient number of quiet periods have passed, the square of a two point derivative of the incoming digital signal is compared to a trip level threshold exceeding the determined noise level to declare a valid trial event. The squaring of the derivative emphasizes the differences between noise and signal, and the valid event is preferably declared when the trip threshold has been exceeded over a temporal comb width to realize a comb over a given time period. Once a trial event has been declared, the event is verified through a spatial comb, which applies the temporal event comb to additional stations. The detector according to the present invention quickly and accurately detects initial compressional waves indicative of a microseismic event which typically exceed the ambient cultural noise level by a small amount, and distinguishes the waves from subsequent larger amplitude shear waves.

Uhl, James Eugene (Albuquerque, NM); Warpinski, Norman Raymond (Albuquerque, NM); Whetten, Ernest Blayne (Albuquerque, NM)

1998-01-01

450

Improved Design of Proportional Integral Derivative Charts  

Microsoft Academic Search

Jiang et al. (2002) introduced proportional integral derivative (PID) control charts for monitoring au- tocorrelated processes based on PID predictors and corresponding residuals. The major contribution of the PID chart is to bridge between engineering process control (EPC) techniques and statistical process control (SPC) schemes. Although the performance of PID charts has been reported in the literature, we focus on

FUGEE TSUNG; YI ZHAO; LIMING XIANG; WEI JIANG

2006-01-01

451

Method of Obtaining S-Triazine Derivatives.  

National Technical Information Service (NTIS)

A method of obtaining derivatives of S-triazines as found in 2-((R-chloro-)triazin-2-yl)amino)butyronitrile where R is the alkylamino-, dialkylamino-, or the 2-((2-nitrilo)propyl)amino group is distinguished by the fact that cyanuric chloride is subjected...

F. V. Avetisyan V. V. Dovlatyan

1972-01-01

452

The Solubility of Some Azafullerene Derivatives  

Microsoft Academic Search

Several fulleroaziridines, azafulleroids and chiral cage-opened ketolactams were synthesized from alkyl azides and C60. Their solubility in various solvents was evaluated by HPLC. It depends both on the starting azide and the linker group. Moreover, the formation of two sp carbons (entries 2) and then of carbonyl derivatives (entries 3) induces a decrease of the polarizability of the C60 moiety

G. Le Strat; N. Noiret; A. Roucoux; H. Patin

1999-01-01

453

Ecosystem Services Derived from Headwater Catchments  

EPA Science Inventory

We used data from the USEPA?s wadeable streams assessment (WSA), US Forest Service?s forest inventory and analysis (FIA), and select USFS experimental forests (EF) to investigate potential ecosystems services derived from headwater catchments. C, N, and P inputs to these catchmen...

454

On Deriving CED Effects from the PIC  

Microsoft Academic Search

This article shows that a version of the Condition on Extraction Domain (Huang 1982) can be derived from the Phase Impenetrability Condition (PIC; Chomsky 2001, 2008) if the following assumptions are made: (a) All syntactic operations are driven by features of lexical items. (b) These features are ordered on lexical items. (c) All phrases are phases. (d) Edge features that

Gereon Müller

2010-01-01

455

Radon-Nikodym Derivatives of Gaussian Measures  

Microsoft Academic Search

We give simple necessary and sufficient conditions on the mean and covariance for a Gaussian measure to be equivalent to Wiener measure. This was formerly an unsolved problem [26]. An unsolved problem is to obtain the Radom-Nikodym derivative $d\\\\mu\\/d\\\

L. A. Shepp

1966-01-01

456

New norbornyl derivatives as woody fragrant materials.  

PubMed

The optimization of a Diels-Alder reaction to prepare a novel ketone bearing a 2,3-dimethylnorbornyl group is presented together with the structure elucidation of the isomers. Employing this new ketone as starting material, derivatives with new woody odor notes as well as attempts to obtain ambery-musky odorants are reported. PMID:18618398

Muratore, Agnès; Duñach, Elisabet; Clinet, Jean-Claude; Plessis, Caroline

2008-06-01

457

Derivatives and the Graphs of Functions Microworld  

NSDL National Science Digital Library

The purpose of this Microworld is to experiment with some of the general applications of the derivative to the study of the behavior of functions. This includes their critical behavior, their local extrema, regions of monotonicity (increasing or decreasing), and their inflection points.

White, James

2004-11-01

458

Metal-carboxylic Acids and Their Derivatives  

NASA Astrophysics Data System (ADS)

Questions connected with the synthesis of metal-carboxylic acids, compounds incorporating [M]-COOH fragments with a metal-carbon bond in which M is a transition metal complex, and their derivatives (salts, esters, and amides) are considered. The bibliography includes 189 references.

Kolomnikov, I. S.; Lysyak, T. V.; Rusakov, S. L.; Kharitonov, Yu Ya

1988-05-01

459

Tectonic plate motions derived from Lageos  

Microsoft Academic Search

Five years of laser data (1984-88) between the Lageos satellite and the ground station network based on precise monthly computations of the Lageos satellite are analyzed to recover tectonic motions affecting the stations. A global inversion over this period provides solutions for absolute velocities in latitude and longitude of a selected subset of 14 stations. Relative horizontal velocities are derived

R. Biancale; A. Cazenave; K. Dominh

1991-01-01

460

Synthesis and Antimicrobial Evaluation of Some New Thiazoline and Thiazolidinone Derivatives Incorporating [1,2,4]Triazolo[1,5-a]benzimidazole  

PubMed Central

Two new series of 3-[2-(3,4-disubstituted-2,3-dihydrothiazol-2-ylidene)hydrazonopropylidenyl]-2-(methylthio)-3H-[1,2,4]triazolo[1,5-a]benzimidazole (6-29) and 3-[2-(3-substituted-4-oxothiazolidin-2-ylidene)hydrazonopropylidenyl]-2-(methylthio)-3H-[1,2,4]triazolo[1,5-a]benzimidazole (30-33) were synthesised starting from 1-[2-(methylthio)-3H-[1,2,4]triazolo[1,5-a]benzimidazol-3-yl] acetone N4-alkyl (aryl) thiosemicarbazones (2-5). Chemical structures of the compounds have been elucidated by different spectral data as well as elemental microanalysis. The newly synthesised compounds were tested for their in vitro antimicrobial activity using the standard agar cup diffusion method. Results revealed that most of the test compounds showed promising broad spectrum antibacterial and antifungal profiles against tested microorganisms, relative to references.

Mahmoud, A. M.; Salem, Ola I. A.; Abdel Moty, Samia G.; Abdel Alim, A. M.

2013-01-01

461

Bacterial degradation of chlorophenols and their derivatives.  

PubMed

Chlorophenols (CPs) and their derivatives are persistent environmental pollutants which are used in the manufacture of dyes, drugs, pesticides and other industrial products. CPs, which include monochlorophenols, polychlorophenols, chloronitrophenols, chloroaminophenols and chloromethylphenols, are highly toxic to living beings due to their carcinogenic, mutagenic and cytotoxic properties. Several physico-chemical and biological methods have been used for removal of CPs from the environment. Bacterial degradation has been considered a cost-effective and eco-friendly method of removing CPs from the environment. Several bacteria that use CPs as their sole carbon and energy sources have been isolated and characterized. Additionally, the metabolic pathways for degradation of CPs have been studied in bacteria and the genes and enzymes involved in the degradation of various CPs have been identified and characterized. This review describes the biochemical and genetic basis of the degradation of CPs and their derivatives. PMID:24589366

Arora, Pankaj Kumar; Bae, Hanhong

2014-01-01

462

Mantle-derived Archaean monzodiorites and trachyandesites  

NASA Technical Reports Server (NTRS)

Geochemical data on monzodiorites and trachyandesites from the Rainy Lake area in Ontario which are strongly enriched in large-ion lithophile elements (LILE) are presented. It is concluded that they are derived by direct melting of the mantle at depths of less than 50 km in either anhydrous or hydrous conditions. Their rare earth element abundances and initial Nd-143/Nd-144 ratios suggest that their mantle sources were enriched in LILE shortly before melting. The monzodiorites-trachyandesites and their granodioritic derivatives may comprise up to 20 percent of the exposed igneous rocks in the Rainy Lake region and Vermilion District. If these rocks are as abundant in other Archaean terranes, a significant part of the early continental crust could have formed by direct melting of LILE-enriched mantle.

Shirey, S. B.; Hanson, G. N.

1984-01-01

463

Hydrocarbon and nonhydrocarbon derivatives of cyclopropane  

NASA Technical Reports Server (NTRS)

The methods used to prepare and purify 19 hydrocarbon derivatives of cyclopropane are discussed. Of these hydrocarbons, 13 were synthesized for the first time. In addition to the hydrocarbons, six cyclopropylcarbinols, five alkyl cyclopropyl ketones, three cyclopropyl chlorides, and one cyclopropanedicarboxylate were prepared as synthesis intermediates. The melting points, boiling points, refractive indices, densities, and, in some instances, heats of combustion of both the hydrocarbon and nonhydrocarbon derivatives of cyclopropane were determined. These data and the infrared spectrum of each of the 34 cyclopropane compounds are presented in this report. The infrared absorption bands characteristic of the cyclopropyl ring are discussed, and some observations are made on the contribution of the cyclopropyl ring to the molecular refractions of cyclopropane compounds.

Slabey, Vernon A; Wise, Paul H; Gibbons, Louis C

1953-01-01