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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

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

PubMed

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 mug mL(-1) and 0.058-3.285 mug 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. PMID:17671609

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

2007-01-01

3

Antioxidant activities of thiosemicarbazones from substituted benzaldehydes and N-(tetra-O-acetyl-?-D-galactopyranosyl)thiosemicarbazide.  

PubMed

Reaction of N-(2,3,4,6-tetra-O-acetyl-?-d-galactopyranosyl)thiosemicarbazide and different substituted benzaldehydes gave some new substituted benzaldehyde N-(2,3,4,6-tetra-O-acetyl-?-d-galactopyranosyl)thiosemicarbazones. 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 ESI-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. Amongst the compounds screened for antioxidant activity, thiosemicarbazones 4a, 4b and 4c showed good antioxidant activity on DPPH. The compounds 4g, 4i, 4l caused significant elevation of SOD activity and 4e, 4g, 4i, 4l had higher catalase activity, and only compounds 4c and 4f expressed the GSH-Px activity. PMID:23291121

Nguyen, Dinh Thanh; Le, The Hoai; Bui, Thi Thu Trang

2012-10-11

4

Synthesis and antityrosinase mechanism of benzaldehyde thiosemicarbazones: novel tyrosinase inhibitors.  

PubMed

p-Hydroxybenzaldehyde thiosemicarbazone (HBT) and p-methoxybenzaldehyde thiosemicarbazone (MBT) were synthesized and established by (1)H NMR and mass spectra. Both compounds were evaluated for their inhibition activities on mushroom tyrosinase and free-cell tyrosinase and melanoma production from B(16) mouse melanoma cells. Results showed that both compounds exhibited significant inhibitory effects on the enzyme activities. HBT and MBT decreased the steady state of the monophenolase activity sharply, and the IC(50) values were estimated as 0.76 and 7.0 ?M, respectively. MBT lengthened the lag time, but HBT could not. HBT and MBT inhibited diphenolase activity dose-dependently, and their IC(50) values were estimated as 3.80 and 2.62 ?M, respectively. Kinetic analyses showed that inhibition type by both compounds was reversible and their mechanisms were mixed-type. Their inhibition constants were also determined and compared. The research may supply the basis for the development of new food preservatives and cosmetic additives. PMID:22250887

Chen, Liang-Hua; Hu, Yong-Hua; Song, Wei; Song, Kang-Kang; Liu, Xuan; Jia, Yu-Long; Zhuang, Jiang-Xing; Chen, Qing-Xi

2012-02-03

5

Structural requirement(s) of N-phenylthioureas and benzaldehyde thiosemicarbazones as inhibitors of melanogenesis in melanoma B 16 cells  

Microsoft Academic Search

In order to define the structural requirements of phenylthiourea (PTU), a series of thiourea and thiosemicarbazone analogs were prepared and evaluated as inhibitors of melanogenesis in melanoma B16 cells. The most potent analog was 2-(4-tert-butylbenzylidene)hydrazinecarbothioamide (1u) with an IC50 value of 2.7?M in inhibition of melanogenesis. The structure for potent inhibitory activity of these derivatives are required with the direct

P. Thanigaimalai; Tuan Anh Le Hoang; Ki-Cheul Lee; Seong-Cheol Bang; Vinay K. Sharma; Cheong-Yong Yun; Eunmiri Roh; Bang-Yeon Hwang; Youngsoo Kim; Sang-Hun Jung

2010-01-01

6

Synthesis and in vitro antiprotozoal activity of 5-nitrothiophene-2-carboxaldehyde thiosemicarbazone derivatives  

Microsoft Academic Search

Several thiosemicarbazone derivatives of 5-nitrothiophene-2-carboxaldehyde were prepared by the simple process in which N4-thiosemicarbazone moiety was replaced by aliphatic, arylic and cyclic amine. Among these thiosemicarbazones compound 11 showed significant antiamoebic activity whereas compound 3 was more active antitrichomonal than the reference drug.

Neelam Bharti; Kakul Husain; M. T Gonzalez Garza; Delia E Cruz-Vega; J Castro-Garza; Benito D Mata-Cardenas; Fehmida Naqvi; Amir Azam

2002-01-01

7

Synthesis and antitumor activity of liquiritigenin thiosemicarbazone derivatives.  

PubMed

In an attempt to develop potent and selective antitumor agents, a series of liquiritigenin thiosemicarbazone derivatives were designed and synthesized. The cytotoxicities of these compounds were evaluated in vitro against K562, DU-145, SGC-7901, HCT-116 and Hela cell lines. The pharmacological results showed that most of the prepared compounds displayed excellent selective cytotoxicity toward K562 and DU-145 cells. From the structure-activity relationships we may conclude that the introduction of a thiosemicarbazone functional group at the 4-position in the skeleton of liquiritigenin is associated with an increase in cytotoxicity. PMID:20494492

Hu, Kun; Yang, Ze-Hua; Pan, Sha-Sha; Xu, Hua-Jin; Ren, Jie

2010-05-06

8

Synthesis, anti- Toxoplasma gondii and antimicrobial activities of benzaldehyde 4-phenyl-3-thiosemicarbazones and 2-[(phenylmethylene)hydrazono]-4-oxo-3-phenyl-5-thiazolidineacetic acids  

Microsoft Academic Search

In the present communication, a new series of 2-[(phenylmethylene)hydrazono]-4-oxo-3-phenyl-5-thiazolidineacetic acids (2a–p) have been synthesized. Benzaldehyde 4-phenyl-3-thiosemicarbazones substituted (1a–p) were also obtained and used as intermediate to give the title compounds. All synthesized compounds were characterized by IR, 1H and 13C NMR. The in vitro anti-Toxoplasma gondii activity of 1a–p and 2a–p was evaluated. The 4-thiazolidinones (2a–p) were screened for their

Thiago M. de Aquino; André P. Liesen; Rosa E. A. da Silva; Vânia T. Lima; Cristiane S. Carvalho; Antônio R. de Faria; Janete M. de Araújo; José G. de Lima; Antonio J. Alves; Edésio J. T. de Melo; Alexandre J. S. Góes

2008-01-01

9

Synthesis, spectral studies and screening for amoebicidal activity of new palladium(II) complexes derived from thiophene-2-carboxaldehyde thiosemicarbazones  

Microsoft Academic Search

In view of the antiamoebic properties observed for many thiophene-2-carboxaldehyde thiosemicarbazones, a series of N4-substituted thiosemicarbazones metal complexes derived from thiophene-2-carboxaldehyde was prepared for evaluation against Entamoeba histolytica. Reaction of thiophene-2-carboxaldehyde with cycloalkylaminothiocarbonylhydrazines having different amines gave the corresponding thiosemicarbazones. Reaction of latter with [Pd(DMSO)2Cl2] gave requisite palladium thiosemicarbazone complexes of the type [Pd(TSC)Cl2] (where TSC=thiosemicarbazones). Screening of antiamoebic activity

Fehmida Naqvi; Amir Azam

2003-01-01

10

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; Silva, Jeferson G Da; Silva, Nayane F; Vilela, Camila F; Mendes, Isolda C; Takahashi, Jacqueline A; Beraldo, Heloisa

2013-10-14

11

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

2010-11-25

12

The antimicrobial activity of lapachol and its thiosemicarbazone and semicarbazone derivatives.  

PubMed

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. PMID:23778660

Souza, Marina Azevêdo; Johann, Susana; Lima, Luciana Alves Rodrigues dos Santos; Campos, Fernanda Fraga; Mendes, Isolda Castro; Beraldo, Heloisa; de Souza-Fagundes, Elaine Maria; Cisalpino, Patrícia Silva; Rosa, Carlos Augusto; Alves, Tânia Maria de Almeida; de Sá, Nívea Pereira; Zani, Carlos Leomar

2013-05-01

13

Aryl- and heteroaryl-thiosemicarbazone derivatives and their metal complexes: a pharmacological template.  

PubMed

In this review, we discuss the current patents concerning aryl/heteroaryl thiosemicarbazone derivatives as regards to their activities and properties, including coordination (chelation) properties. The mode of action of the aryl/heteroaryl thiosemicarbazone derivatives involves metal coordination with proteins or biological fluids that have metal ions in their structure. Additionally, these molecules can also form multiple hydrogen bonds through their (thio) amide and N3 nitrogen that ensure a strong interaction with the receptor. In some cases, strong ?-? interactions can be observed too. Special attention is given to pyridyl, bis-pyridyl, benzoylpyridyl and isatin thiosemicarbazone derivatives that exhibit significant anticancer, antiviral and other activities in free and in metal complexed forms. This key biological role is often related with their capability to inhibit the enzyme ribonucleotide reductase, similar to what is observed with potent anticancer drugs such as Triapine and methisazone. Recent studies have revealed that thiosemicarbazone can also inhibit topoisomerase II ? enzyme. Thiosemicarbazone derivatives form coordination complex with various metals such as Zn, Cu, Fe, Co, Ni, Pt, Pd, etc., and these complexes provide better activities than the free thiosemicarbazones. Recent patents show that the controlled or sustained release dosage form of the thiosemicarbazone derivatives along with ionizing radiations is used for the treatment of proliferative diseases (US20110152281, US20110245304, US20120172217). PMID:22963201

Moorthy, Narayana S H N; Cerqueira, Nuno M F S A; Ramos, Maria J; Fernandes, Pedro A

2013-05-01

14

A combined experimental and quantum chemical studies on molecular structure, spectral properties, intra and intermolecular interactions and first hyperpolarizability of 4-(benzyloxy)benzaldehyde thiosemicarbazone and its dimer  

NASA Astrophysics Data System (ADS)

In the present work, a detailed spectroscopic analysis of 4-(benzyloxy)benzaldehyde thiosemicarbazone (3) has been carried out using 1H NMR, 13C NMR, UV-Visible and FT-IR spectroscopic techniques. The quantum chemical calculations have been carried out using DFT level of theory, B3LYP functional and 6-31G(d,p) basis set. The calculated thermodynamic parameters show that the formation of 3 is an exothermic and spontaneous reaction at 25 °C. The vibrational analysis indicates the formation of dimer in the solid state by intermolecular hydrogen bonding (NH⋯SC) and the binding energy of dimer is calculated to be 11.2 kcal/mol, using DFT calculation. NBO analysis is carried out to investigate the charge transfer in various intra and intermolecular interactions involved in dimer. Topological parameters at bond critical points (BCPs) are calculated to analyze the strength and nature of various intra and intermolecular interactions in dimer by Bader's 'Atoms in molecules' AIM theory in detail. The local reactivity descriptors such as Fukui functions (fk+,fk-), local softnesses (sk+,sk-) and electrophilicity indices (?k+,?k-) analysis are performed to determine the reactive sites within molecule. Non linear optical (NLO) behavior of title compound is investigated by the computed value of first hyperpolarizability (?0).

Kumar, Amit; Rawat, Poonam; Baboo, Vikas; Verma, Divya; Singh, R. N.; Saxena, Deepti; Gauniyal, H. M.; Pandey, Anoop Kumar; Pal, Harish

2013-02-01

15

Analytical properties of p-[N,N-bis(2-chloroethyl)amino]benzaldehyde thiosemicarbazone: spectrophotometric determination of palladium(II) in alloys, catalysts, and complexes.  

PubMed

p-[N,N-bis(2-chloroethyl)amino]benzaldehyde thiosemicarbazone (CEABT) is proposed as a new, sensitive, and selective analytical reagent for the spectrophotometric determination of palladium(II). The reagent reacts with palladium(II) in the pH range 1-2 to form a yellow-colored complex. Beer's law is obeyed in the concentration range up to 2.64 ?g cm(-3). The optimum concentration range for minimum photometric error as determined by Ringbom's plot method is 0.48-2.40 ?g cm(-3). The yellowish Pd(II)-reagent complex shows a maximum absorbance at 395 nm, with molar absorptivity of 4.05×10(4) dm3 mol(-1) cm(-1) and Sandell's sensitivity of the complex from Beer's data, for D=0.001, is 0.0026 ?g cm(-2). The composition of the Pd(II)-CEABT reagent complex is found to be 1:2 (M-L). The interference of various cations and anions in the method were studied. The proposed method was successfully used for the determination of Pd(II) in alloys, catalysts, complexes, water samples, and synthetic alloy mixtures with a fair degree of accuracy. PMID:20229165

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

2010-03-13

16

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

2010-07-07

17

DNA binding, DNA cleavage, antioxidant and cytotoxicity studies on ruthenium(II) complexes of benzaldehyde 4-methyl-3-thiosemicarbazones  

NASA Astrophysics Data System (ADS)

Four new ruthenium(II) complexes with N(4)-methyl thiosemicarbazone ligands, (E)-2-(2-chlorobenzylidene)-N-methylhydrazinecarbothioamide (HL1) and (E)-N-methyl-2-(2-nitrobenzylidene)hydrazinecarbothioamide (HL2), were prepared and fully characterized by various spectro-analytical techniques. The Schiff bases act as bidentate, monobasic chelating ligands with S and N as the donor sites and are preferably found in the thiol form in all the complexes studied. The molecular structure of HL1 and HL2 were determined by single crystal X-ray diffraction method. DNA binding of the compounds was investigated by absorption spectroscopy which indicated that the complexes bind to DNA via intercalation. The oxidative cleavage of the complexes with CT-DNA inferred that the effects of cleavage are dose dependent. Antioxidant studies of the ligands and complexes showed the significant antioxidant activity against DPPH radical. In addition, the in vitro cytotoxicity of the ligands and complexes against MCF-7 cell line was assayed which showed higher cytotoxic activity with the lower IC50 values indicating their efficiency in killing the cancer cells even at low concentrations.

Sampath, Krishnan; Sathiyaraj, Subbaiyan; Jayabalakrishnan, Chinnasamy

2013-03-01

18

Inhibition of Zinc Corrosion by Some Benzaldehyde Derivatives in HCl Solution  

NASA Astrophysics Data System (ADS)

The effect of some benzaldehyde derivatives on the corrosion of zinc in 0.5 M HCl solution is studied in this article using mass loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) techniques. The percentage inhibition efficiency (%In) was found to increase with increasing concentration of the inhibitor and with decreasing temperature. Polarization studies indicated that all of the compounds studied are mixed-type inhibitors. The inhibitive action of these benzaldehyde derivatives has been discussed in view of the adsorption on the zinc surface. The adsorption process follows Temkin's isotherm. The addition of KSCN, KI, and KBr to benzaldehyde derivatives has enhanced the inhibition efficiency because of synergistic effect. The mechanism of inhibition process is discussed in the light of the chemical structures of the investigated inhibitors.

Abdallah, M.; Zaafarany, I.; Fouda, A. S.; Abd El-Kader, D.

2012-06-01

19

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

20

Cytotoxic activity, albumin and DNA binding of new copper(II) complexes with chalcone-derived thiosemicarbazones.  

PubMed

[Cu(HL)Cl2] complexes of chalcone-derived thiosemicarbazones were obtained with 3-phenyl-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone (HPyCTPh), complex (1), 3-(4-chlorophenyl)-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone (HPyCT4ClPh), complex (2), 3-(4-bromophenyl)-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone (HPyCT4BrPh), complex (3), and 3-(4-nitrophenyl-1-pyridin-2-ylprop-2-en-1-one thiosemicarbazone (HPyCT4NO2Ph), complex (4). 1-3 showed interaction with bovine serum albumin (BSA) and deoxyribonucleic acid from calf thymus (CT-DNA). The cytotoxic activities of the thiosemicarbazones and complexes (1-4) were tested against HL60 (wild type human promyelocytic leukemia), Jurkat (human immortalized line of T lymphocyte), MDA-MB 231 (human breast carcinoma) and HCT-116 (human colorectal carcinoma) tumor cell lineages. Upon coordination to copper(II) cytotoxicity significantly increased in Jurkat, MDA-MB 231 and HCT-116 cells. Unlike the free thiosemicarbazones, 1-4 induced DNA fragmentation in solid tumor cells indicating their pro-apoptotic potential. PMID:23747809

Da Silva, Jeferson G; Recio Despaigne, Angel A; Louro, Sonia R W; Bandeira, Cristiano C; Souza-Fagundes, Elaine M; Beraldo, Heloisa

2013-05-16

21

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

22

Iron(III) complexes of some thiosemicarbazones derived from 2-acetylpyridine, its 6-methyl derivative and its N -oxide  

Microsoft Academic Search

A series of iron(III) complexes of thiosemicarbazones derived from 2-acetylpyridine, 6-methyl-2-acetylpyridine and 2-acetylpyridineN-oxide have been prepared from Fe(ClO4)3 and FeCl3. All of the isolated solids have cations involving two monobasic tridentate ligands, and either perchlorate or tetrachloroferrate(III) anions and are 1:1 electrolytes. Coordinationvia the pyridine nitrogen (or theN-oxide oxygen), the imine nitrogen and the sulphur atom are confirmed by infrared

Douglas X. West; Patricia M. Ahrweiler; Gözen Ertem; John P. Scovill; Daniel L. Klayman; Judith L. Flippen-Anderson; Richard Gilardi; Clifford George; Lewis K. Pannell

1985-01-01

23

Evaluation of DNA-binding, DNA cleavage, antioxidant and cytotoxic activity of mononuclear ruthenium(II) carbonyl complexes of benzaldehyde 4-phenyl-3-thiosemicarbazones  

NASA Astrophysics Data System (ADS)

Two 4-phenyl-3-thiosemicarbazone ligands, (E)-2-(2-chlorobenzylidene)-N-phenylhydrazinecarbothioamide (HL1) and (E)-2-(2-nitrobenzylidene)-N-phenylhydrazinecarbothioamide (HL2), and its ruthenium(II) complexes were synthesized and characterized by physico-chemical and spectroscopic methods. The Schiff bases act as bidentate, monobasic chelating ligands with S and N as the donor sites and are preferably found in the thiol form in all the complexes studied. The molecular structure of HL1 and HL2 were determined by single crystal X-ray diffraction method. DNA binding of the compounds was investigated by absorption spectroscopy which indicated that the compounds bind to DNA via intercalation. The oxidative cleavage of the complexes with CT-DNA inferred that the effects of cleavage are dose dependent. Antioxidant study of the ligands and complexes showed significant antioxidant activity against DPPH radical. In addition, the in vitro cytotoxicity of the ligands and complexes assayed against HeLa and MCF-7 cell lines showed higher cytotoxic activity with the lower IC50 values indicating their efficiency in killing the cancer cells even at low concentrations.

Sampath, Krishnan; Sathiyaraj, Subbaiyan; Jayabalakrishnan, Chinnasamy

2013-11-01

24

Structure effect of some thiosemicarbazone derivatives on the corrosion inhibition of Fe 78B 13Si 9 glassy alloy in Na 2SO 4 solution  

Microsoft Academic Search

The corrosion and corrosion inhibition of Fe78B13Si9 glassy alloy by some thiosemicarbazone derivatives in 0.2 M Na2SO4 solution containing 10% MeOH has been studied. Inhibitors efficiency was estimated from electrochemical (polarization and impedance) measurements. Nearly identical results obtained from both techniques and morphological study are consistent. The thiosemicarbazone derivatives gave maximum corrosion inhibition of the alloy in 0.2 M Na2SO4 solution and

S. T. Arab; K. M. Emran

2008-01-01

25

Palladium(II) complexes of NS donor ligands derived from steroidal thiosemicarbazones as antibacterial agents.  

PubMed

We have investigated the antibacterial activity of some new steroidal thiosemicarbazones and their Pd(II) metal complexes were prepared by the reaction of the thiosemicarbazones with [Pd(DMSO)(2)Cl(2)]. The steroidal thiosemicarbazones were prepared by the reaction of thiosemicarbazides with a steroidal ketone. The structures of these compounds were elucidated by IR, (1)H-NMR, (13)C-NMR, FAB mass spectroscopic methods, elemental analyses and TGA analysis. The antibacterial activity of these compounds were tested in vitro by the disk diffusion assay against two Gram-positive and two Gram-negative bacteria. The results showed that steroidal complexes are better inhibitors of both types of the bacteria (Gram-positive and Gram-negative) as compared to steroidal thiosemicarbazones. Compound Ia displays remarkable antibacterial activity as compared to amoxicillin. PMID:20657393

Asiri, Abdullah M; Khan, Salman A

2010-07-08

26

Thiosemicarbazone complexes of the platinum metals. A story of variable coordination modes  

Microsoft Academic Search

Salicylaldehyde thiosemicarbazone (H2saltsc) reacts with [M(PPh3)3X2] (M = Ru, Os; X = Cl, Br) to afford complexes of type [M(PPh3)2(Hsaltsc)2], in which the salicylaldehyde thiosemicarbazone ligand is coordinated to the metal as a bidentate N,S-donor forming a four-membered\\u000a chelate ring. Reaction of benzaldehyde thiosemicarbazones (Hbztsc-R) with [M(PPh3)3X2] also affords complexes of similar type, viz. [M(PPh3)2(bztsc-R)2], in which the benzaldehyde thiosemicarbazones

Indrani Pal; Falguni Basuli; Samaresh Bhattacharya

2002-01-01

27

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

28

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

29

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

30

Cyclooctadiene Ru(II) complexes of thiophene-2-carboxaldehyde-derived thiosemicarbazones: synthesis, characterization and antiamoebic activity  

Microsoft Academic Search

Thiosemicarbazones (TSC) 1–10 were synthesized by condensing substituted thiosemicarbazide with thiophene-2-carboxaldehyde. These thiosemicarbazones were further reacted with [Ru(?4 –C8H12)(CH3CN)2Cl2] to form complexes of the type [Ru(?4 –C8H12)(TSC)Cl2] 1a–10a. Thiosemicarbazones exhibited antiamoebic activity in the range IC50=1.09–5.42 ?M. In vitro assessment of antiamoebic activity indicated that the thiosemicarbazones 3, IC50=1.67 ?M, 4, IC50=1.11 ?M and 6, IC50=1.09 ?M showed substantially less

Shailendra Singh; Fareeda Athar; Mannar R. Maurya; Amir Azam

2006-01-01

31

New iron(III) complexes with thiosemicarbazones derived from 5-methyl-3-formylpyrazole  

Microsoft Academic Search

New iron(III) complexes of 5-methyl-3-formylpyrazole thiosemicarbazone (HMPzTS) and 5-methyl-3-formylpyrazole-4-phenylthiosemicarbazone (HMPzPTS), namely [Fe(MPzTS)2]X and [Fe(MPzPTS)2]X respectively, where X=Cl, NO3, SCN and ClO4, have been synthesised and physico-chemically characterised by magnetic measurements (polycrystalline state), electronic, i.r., e.s.r. and Mössbauer spectra. All are cationic complexes containing two monoprotonic tridentate ligands with NNS donor sites and an anionic counterpart; they behave as 1:1 electrolytes

Pulakesh Bera; Nityananda Saha; Sanjay Kumar; D. Banerjee; R. Bhattacharya

1999-01-01

32

One-Pot Synthesis of Some New Semicarbazone, Thiosemicarbazone, and Hydrazone Derivatives of 1Phenyl3-Arylpyrazole-4-Carboxaldehyde from Acetophenone Phenylhydrazones Using Vilsmeier–Haack Reagent  

Microsoft Academic Search

Semicarbazone derivatives 3 of 1,3-diphenylpyrazole-4-carboxaldehyde have been synthesized in high yields through a one-pot procedure involving acetophenone phenylhydrazones 1 subjected to Vilsmeier double formylation and workup under new conditions (i.e., treatment with semicarbazide followed by sodium bicarbonate). This method is even suitable for preparing other derivatives (i.e., thiosemicarbazones 4 and hydrazones 5) in high yields.

Rashmi Pundeer; Pooja Ranjan; Kamaljeet Pannu; Om Prakash

2008-01-01

33

Cytotoxicity of imides-N-alkyl semicarbazones, thiosemicarbazones, acetylhydrazones and related derivatives.  

PubMed

The semicarbazones, thiosemicarbazones and acetyl-hydrazones of phthalimide, o-benzosulfimide, naphthalimide and diphenimide demonstrated potent cytotoxicity against murine and human leukemia cell growth and cultured cell growth from human solid tumors. The major site of inhibition in L1210 leukemia cells was DNA synthesis after 60 min incubated with the agents at 25, 50 and 100 microM. De novo synthesis of purines at the regulatory enzyme sites of PRPP amidotransferase and IMP dehydrogenase were the major targets of the agent. Thymidylate synthetase, dihydrofolate reductase and ribonucleoside reductase activities were inhibited by the agents in a manner which would contribute to the overall reduction of DNA synthesis and cell death. d(NTP) pools were significantly reduced and the evidence suggests that the agents interacted with DNA affording DNA strand scission which would interfere with both template utilization by the polymerases and also ultimately reduce nucleic acid synthesis. PMID:7756677

Hall, I H; Wong, O T; Chapman, J M

1995-02-01

34

Electrophilicities of benzaldehyde-derived iminium ions: quantification of the electrophilic activation of aldehydes by iminium formation.  

PubMed

Rate constants for the reactions of benzaldehyde-derived iminium ions with C-nucleophiles (enamines, silylated ketene acetals, and enol ethers) have been determined photometrically in CH3CN solution and used to determine the electrophilicity parameters E of the cations defined by the correlation log k(20°C) = s(N)(E + N) (Mayr, H.; et al. J. Am. Chem. Soc. 2001, 123, 9500-9512). With electrophilicity parameters from E = -10.69 (Ar = p-MeOC6H4) to E = -8.34 (Ar = p-CF3), the iminium ions Ar-CH?NMe2(+) have almost the same reactivities as analogously substituted arylidenemalononitriles Ar-CH?C(CN)2 and are 10 orders of magnitude more reactive than the corresponding aldehydes. The rate constants for the reactions of iminium ions with amines and water in acetonitrile are 10(3)-10(5) times faster than predicted by the quoted correlation, which is explained by the transition states which already experience the anomeric stabilization of the resulting N,N- and O,N-acetals. PMID:23570344

Appel, Roland; Chelli, Saloua; Tokuyasu, Takahiro; Troshin, Konstantin; Mayr, Herbert

2013-04-23

35

Spectroscopic study of Hg (II)-complex with 4-(dimethylamino)benzaldehyde 4-ethylthiosemicarbazone  

Microsoft Academic Search

This study reported on a newly synthesized Hg (II)-thiosemicarbazone complex. The complex was characterized using uv-visible spectrophotometry. The mercury (II) - 4-(Dimethylamino)benzaldehyde 4-ethylthiosemicarbazone (DMABET) in methanol had a maximum absorbance (?max) at 374 nm, whereas the ?max for DMABET in methanol was 356 nm. At optimum pH i.e. pH 4 ?max had shifted to 381 nm. The molar stoichiometry of

Tara F. Tahir; A. Salhin; S. A. Ghani

2010-01-01

36

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

37

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

PubMed Central

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 in India such as Japanese Encephalitis Virus (JEV), Dengue-2 (Den-2) and West Nile viruses (WNV). Results Amongst the fourteen Mannich bases of MIBT derivatives tested one compound – SCH 16 was able to completely inhibit in vitro Japanese encephalitis virus (JEV) and West Nile virus (WNV) replication. However no antiviral activity of SCH 16 was noted against Den-2 virus replication. This compound was able to inhibit 50% of the plaques (IC50) produced by JEV and WNV at a concentration of 16 ?gm/ml (0.000025 ?M) and 4 ?gm/ml (0.000006 ?M) respectively. Furthermore, SCH 16 at a concentration of 500 mg/kg body weight administered by oral route twice daily was able to completely (100%) prevent mortality in mice challenged with 50LD50 JEV by the peripheral route. Our experiments to understand the mechanism of action suggest that SCH 16 inhibited JEV replication at the level of early protein translation. Conclusion Only one of the 14 isatin derivatives -SCH 16 exhibited antiviral action on JEV and WNV virus infection in vitro. SCH 16 was also found to completely inhibit JEV replication in vivo in a mouse model challenged peripherally with 50LD50 of the virus. These results warrant further research and development on SCH 16 as a possible therapeutic agent.

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

2008-01-01

38

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

39

Zinc(II) complexes derived from pyridine-2-carbaldehyde thiosemicarbazone and (1E)-1-pyridin-2-ylethan-1-one thiosemicarbazone. Synthesis, crystal structures and antiproliferative activity of zinc(II) complexes.  

PubMed

The complexes [ZnCl(2)(HFoTsc)xH(2)O], [Zn(FoTsc)(2)], [ZnCl(2)(HAcTsc)xH(2)O] and [Zn(AcTsc)(2)], where HFoTsc and HAcTsc is pyridine-2-carbaldehyde thiosemicarbazone and (1E)-1-pyridin-2-ylethan-1-one thiosemicarbazone respectively, have been prepared and structurally characterized by means vibrational, and NMR ((1)H and (13)C) spectroscopy. The crystal structures of the complexes [ZnCl(2)(HFoTsc)xH(2)O], [Zn(AcTsc)(2)] and [ZnCl(2)(HAcTsc)xH(2)O] have been determined by X-ray crystallography. The metal co-ordination geometry of [ZnCl(2)(HFoTsc)xH(2)O] and [ZnCl(2)(HAcTsc)xH(2)O] is described as distorted square pyramidal and the two complexes are self-assembled via pi-->pi stacking interactions and intermolecular hydrogen bonds. In these two cases molecular recognition of the hydrogen bonds leads to aggregation and a supramolecular assembly of infinite two-dimensional network. The metal co-ordination geometry of [Zn(AcTsc)(2)] is described as distorted octahedral configuration in a trans-N(2)-cis-N(1)-cis-S configuration. HFoTsc and HAcTsc and the zinc complexes have been evaluated for antiproliferative activity in vitro against the cells of two human cancer cell lines: MCF-7 (human breast cancer cell line), T24 (bladder cancer cell line) and a mouse fibroblast L-929 cell line. The cytotoxic activity shown by these compounds indicates that coupling of HFoTsc and HAcTsc to Zn(II) metal center result in metallic complexes with important biological properties since they display IC(50) values in a microM range similar to or better than that of the antitumor drug cis-platin and are considered as agents with potential antitumor activity candidates for further stages of screening in vitro and/or in vivo. PMID:16828164

Kovala-Demertzi, Dimitra; Yadav, Paras Nath; Wiecek, Joanna; Skoulika, Stauroula; Varadinova, Tatiana; Demertzis, Mavroudis A

2006-05-27

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

Structure and antimicrobial activities of benzoyl phenyl-thiosemicarbazone-chitosans.  

PubMed

Previously, we had prepared acetyl phenyl-thiosemicarbazone derivatives of chitosan, and their antimicrobial activities were analyzed. The purpose of the present study was to further assess the relationship between the structure and antimicrobial activities of benzoyl phenyl-thiosemicarbazone-chitosan. Ten new benzoyl phenyl-thiosemicarbazone-chitosans were prepared and their structures were characterized by FT-IR and elemental analysis. The antimicrobial experiment against four species of bacteria and four crop-threatening pathogenic fungi were conducted based on the derivatives of chitosan with different molecular weight at different concentrations. The results indicated that the antimicrobial activities of benzoyl phenyl-thiosemicarbazone derivatives are much better than that of pure CS. The value of the minimum inhibition concentration (MIC) and the minimum bactericidal concentration (MBC) of the derivatives against Escherichia coli was 7.03 and 225 ?g mL(-1) respectively. All of the derivatives had significant inhibiting effect on the investigated fungi in the concentration of 50-500 ?g mL(-1), and the maximum inhibitory index was 94.74%. These results indicate that the derivatives have potential ability used as antibacterial reagent in agricultural field. PMID:22266384

Zhong, Zhimei; Aotegen, Bayaer; Xu, Hui; Zhao, Shuang

2012-01-14

42

Benzaldehyde-functionalized Polymer Vesicles  

PubMed Central

Polymer vesicles with diameters of ca. 100-600 nm and bearing benzaldehyde functionalities within the vesicular walls were constructed through self assembly of an amphiphilic block copolymer PEO45-b-PVBA26 in water. The reactivity of the benzaldehyde functionalities was verified by crosslinking the polymersomes, and also by a one-pot crosslinking and functionalization approach to further render the vesicles fluorescent, each via reductive amination. In vitro studies found these labelled nanostructures to undergo cell association.

Sun, Guorong; Fang, Huafeng; Cheng, Chong; Lu, Peng; Zhang, Ke; Walker, Amy V.; Taylor, John-Stephen A.; Wooley, Karen L.

2009-01-01

43

Synthesis, spectroscopic studies and crystal structure of ( E)-2-(2,4-dihydroxybenzylidene)thiosemicarbazone and ( E)-2-[(1 H-indol-3-yl)methylene]thiosemicarbazone  

Microsoft Academic Search

Thiosemicarbazone Schiff bases (1 and 2) derived from 2,4-dihydroxybenzaldehyde, indoline-3-carbaldehyde and thiosemicarbazone have been synthesized and their structures were elucidated by elemental analysis, FT-IR, 1H NMR, 13C NMR and UV–visible spectroscopic techniques. The structures of compounds 1 and 2 have also been examined cyrstallographically. The title compounds 1 and 2 crystallize in the monoclinic space group C2\\/c and triclinic space

Mustafa Yildiz; Hüseyin Ünver; Digdem Erdener; Askin Kiraz; Nazan Ocak ?skeleli

2009-01-01

44

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

45

Metal-induced cyclization of thiosemicarbazones derived from beta-keto amides and beta-keto esters: open-chain and cyclized ligands in zinc(II) complexes.  

PubMed

The reactions of Zn(OAc)(2) with acetoacetanilide, methyl acetoacetate, o-acetoacetanisidide, and ethyl 2-methylacetoacetate thiosemicarbazones (HTSC(1), HTSC(2), HTSC(3), and HTSC(4), respectively) were explored in methanol. With HTSC(1), HTSC(2), and HTSC(3), following isolation of the corresponding zinc(II) thiosemicarbazonates [Zn(TSC(x))(2)] (x = 1, 2, 3), the mother liquors afforded pyrazolonate complexes [ZnL(1)(2)(H(2)O)] (HL(1) = 2,5-dihydro-3-methyl-5-oxo-1H-pyrazole-1-carbothioamide) that had been formed by cyclization of the corresponding TSC(-). The reaction of HTSC(4) with zinc(II) acetate gave only the pyrazolonate complex [ZnL(2)(2)(H(2)O)] (HL(2) = 2,5-dihydro-3,4-dimethyl-5-oxo-1H-pyrazole-1-carbothioamide). All compounds were studied by IR and NMR spectroscopy, and HTSC(3), [Zn(TSC(3))(2)] x DMSO, [ZnL(1)(2)(H(2)O)] x 2DMSO, and [ZnL(2)(2)(H(2)O)] x 2DMSO were also studied by X-ray diffractometry, giving a thorough picture of the cyclization process. In preliminary tests of the effects of HL(1) and [ZnL(1)(2)(H(2)O)] on rat paw inflammatory edema induced by carrageenan, HL(1) showed antiinflammatory activity. PMID:11896724

Casas, José S; Castaño, María V; Castellano, Eduardo E; Ellena, Javier; García-Tasende, María S; Gato, Angeles; Sánchez, Agustín; Sanjuán, Luisa M; Sordo, José

2002-03-25

46

Synthesis, spectral characterization and biological evaluation of copper(II) and nickel(II) complexes with thiosemicarbazones derived from a bidentate Schiff base  

NASA Astrophysics Data System (ADS)

Complexes of copper(II) and nickel(II) of general composition M(L)2X2, have been synthesized with the ligand 1-Tetralone thiosemicarbazone (where L = 1-Tetralone thiosemicarbazone and X=Cl,1/2SO42-). The molar conductance of the complexes in fresh solution of DMSO lies in the range of 10-20 ?-1 cm2 mol-1 indicating their non-electrolytic behavior. Thus, the complexes may be formulated as [M(L2)X2]. Ligand was characterized by mass, NMR, IR and single crystallographic studies. All the complexes were characterized by elemental analyses, magnetic moments, IR, electronic and EPR spectral studies. The IR spectral data of ligand indicated the involvement of sulfur and azomethine nitrogen in coordination to the central metal ion. The copper(II) and nickel(II) complexes were found to have magnetic moments1.93-1.96 BM and 2.91-2.94 BM corresponding to one and two unpaired electrons respectively. On the basis of molar conductance, EPR, electronic and infrared spectral studies, a tetragonal geometry has been assigned for Cu(II) chloride complex and trigonal bipyramidal to Cu(II) sulfate complex but an octahedral geometry for Ni(II) complexes. Newly synthesized ligand and its Cu(II) and Ni(II) complexes have also been screened against different bacterial and fungal species.

Chandra, Sulekh; Bargujar, Savita; Nirwal, Rita; Yadav, Neesha

2013-04-01

47

Structure-function relationships for a new series of pyridine-2-carboxaldehyde thiosemicarbazones on ribonucleotide reductase activity and tumor cell growth in culture and in vivo  

Microsoft Academic Search

The synthesis of a new series of pyridine-2-carboxaldehyde thiosemicarbazones (HCTs) that have amino groups in the 3- and 5-positions has allowed the comparison of the structure\\/function relationships with regard to inhibition of ribonucleotide reductase activity, L1210 cell growth in culture and L1210 leukemia in vivo.3-Aminopyridine-2-carboxaldehyde thiosemicarbazones are more active than the corresponding 3-hydroxy-derivatives. The 3-amino-2-pyridine carboxaldehyde thiosemicarbazones were also more

Joseph G. Cory; Ann H. Cory; Germana Rappa; Aurelio Lorico; Mao-Chin Llu; Tai-Shun Lin; Alan C. Sartorelli

1995-01-01

48

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

49

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

50

Impact of terminal dimethylation on the resistance profile of ?-N-heterocyclic thiosemicarbazones.  

PubMed

Triapine is an ?-N-heterocyclic thiosemicarbazone with promising anticancer activity against hematologic malignancies but widely ineffective against solid tumor types in clinical trials. The anticancer activity of thiosemicarbazones can be dramatically increased by terminal dimethylation. KP1089 is a gallium compound containing two terminal dimethylated thiosemicarbazone ligands. To gain insights on the vulnerability of this highly active terminal dimethylated thiosemicarbazone to drug resistance mechanisms, a new cell model with acquired resistance against the lead compound KP1089 was established. Subsequent genomic analyses (arrayCGH and FISH) revealed amplification of the ABCC1 gene on double minute chromosomal DNA in KP1089-resistant cells as well as overexpression of ABCC1 and ABCG2 on the protein level. KP1089 was further confirmed as a substrate of ABCC1 and ABCG2 but not of ABCB1 using a panel of ABC transporter-overexpressing cell models as well as ABC transporter inhibitors. Moreover, glutathione depletion strongly enhanced KP1089 activity, although no glutathione conjugate formation by glutathione-S-transferase was observed. Thus, a co-transport of KP1089 together with glutathione is suggested. Finally, a panel of thiosemicarbazone derivatives was tested on the new KP1089-resistant cell line. Notably, KP1089-resistant cells were not cross-resistant against thiosemicarbazones lacking terminal dimethylation (e.g. Triapine) which are less active than KP1089. This suggests that terminal dimethylation of thiosemicarbazones - linked with distinctly enhanced anticancer activity - leads to altered resistance profiles compared to classical thiosemicarbazones making this compound class of interest for further (pre)clinical evaluation. PMID:22426010

Heffeter, Petra; Pirker, Christine; Kowol, Christian R; Herrman, Gerrit; Dornetshuber, Rita; Miklos, Walter; Jungwirth, Ute; Koellensperger, Gunda; Keppler, Bernhard K; Berger, Walter

2012-03-15

51

Impact of terminal dimethylation on the resistance profile of ?-N-heterocyclic thiosemicarbazones  

PubMed Central

Triapine is an ?-N-heterocyclic thiosemicarbazone with promising anticancer activity against hematologic malignancies but widely ineffective against solid tumor types in clinical trials. The anticancer activity of thiosemicarbazones can be dramatically increased by terminal dimethylation. KP1089 is a gallium compound containing two terminal dimethylated thiosemicarbazone ligands. To gain insights on the vulnerability of this highly active terminal dimethylated thiosemicarbazone to drug resistance mechanisms, a new cell model with acquired resistance against the lead compound KP1089 was established. Subsequent genomic analyses (arrayCGH and FISH) revealed amplification of the ABCC1 gene on double minute chromosomal DNA in KP1089-resistant cells as well as overexpression of ABCC1 and ABCG2 on the protein level. KP1089 was further confirmed as a substrate of ABCC1 and ABCG2 but not of ABCB1 using a panel of ABC transporter-overexpressing cell models as well as ABC transporter inhibitors. Moreover, glutathione depletion strongly enhanced KP1089 activity, although no glutathione conjugate formation by glutathione-S-transferase was observed. Thus, a co-transport of KP1089 together with glutathione is suggested. Finally, a panel of thiosemicarbazone derivatives was tested on the new KP1089-resistant cell line. Notably, KP1089-resistant cells were not cross-resistant against thiosemicarbazones lacking terminal dimethylation (e.g. Triapine) which are less active than KP1089. This suggests that terminal dimethylation of thiosemicarbazones – linked with distinctly enhanced anticancer activity – leads to altered resistance profiles compared to classical thiosemicarbazones making this compound class of interest for further (pre)clinical evaluation.

Heffeter, Petra; Pirker, Christine; Kowol, Christian R.; Herrman, Gerrit; Dornetshuber, Rita; Miklos, Walter; Jungwirth, Ute; Koellensperger, Gunda; Keppler, Bernhard K.; Berger, Walter

2012-01-01

52

Efficient synthesis of ribonucleotide reductase inhibitors 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3AP) and 3-amino-4-methylpyridine-2-carboxaldehyde thiosemicarbazone (3AMP) via palladium mediated cross-coupling reactions  

Microsoft Academic Search

An efficient synthesis of potent ribonucleotide reductases inhibitors 3-amino-pyridine-2-carboxaldehyde thiosemicarbazone (3-AP) and 3-amino-4-methyl-pyridine-2-carboxaldehyde thiosemicarbazone (3-AMP) is described. The synthesis of 3-AP and 3-AMP was achieved in 4 and 5 steps, with overall yields of 61% and 39%, respectively. The synthesis featured a convergent approach utilizing a Stille coupling strategy to prepare vinylpyridine derivatives. A more economic way to synthesize vinylpyridine

Jun Li; Shu-Hui Chen; Xiuyan Li; Chuansheng Niu; Terrence W Doyle

1998-01-01

53

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

54

Impact of metal coordination on cytotoxicity of 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (triapine) and novel insights into terminal dimethylation.  

PubMed

The first metal complexes of 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (Triapine) were synthesized. Triapine was prepared by a novel three-step procedure in 64% overall yield. In addition, a series of related ligands, namely, 2-formylpyridine thiosemicarbazone, 2-acetylpyridine thiosemicarbazone, 2-pyridineformamide thiosemicarbazone, and their N(4)-dimethylated derivatives (including the N(4)-dimethylated analogue of Triapine) were prepared, along with their corresponding gallium(III) and iron(III) complexes with the general formula [M(L)(2)](+), where HL is the respective thiosemicarbazone. The compounds were characterized by elemental analysis, (1)H and (13)C NMR, IR and UV-vis spectroscopies, mass spectrometry, and cyclic voltammetry. In addition, Triapine and its iron(III) and gallium(III) complexes were studied by X-ray crystallography. All ligands and complexes were tested for their in vitro antiproliferative activity in two human cancer cell lines (41M and SK-BR-3), and structure-activity relationships were established. In general, the coordination to gallium(III) increased the cytotoxicity while the iron(III) complexes show reduced cytotoxic activity compared to the metal-free thiosemicarbazones. Selected compounds were investigated for the capacity of inhibiting ribonucleotide reductase by incorporation of (3)H-cytidine into DNA. PMID:19637923

Kowol, Christian R; Trondl, Robert; Heffeter, Petra; Arion, Vladimir B; Jakupec, Michael A; Roller, Alexander; Galanski, Markus; Berger, Walter; Keppler, Bernhard K

2009-08-27

55

Toxicologic Evaluation of Isoquinalaldehyde Thiosemicarbazone (Nsc-92188).  

National Technical Information Service (NTIS)

Isoquinalaldehyde thiosemicarbazone (NSC-92188) 18.75 mg/kg administered orally for 14 days to 4 dogs and 2 monkeys produced slight toxic effects as: temporary decrease in leukocytes and temporary hepatotoxicity. The observations that hepatotoxicity faile...

U. Schaeppi

1967-01-01

56

Synthesis, characterization and in vitro Antiamoebic Activity of 5-nitrothiophene-2-carboxaldehyde thiosemicarbazones and their Palladium (II) and Ruthenium (II) Complexes  

Microsoft Academic Search

Synthesis of new Palladium(II) and Ruthenium(II) complexes of the type, [Pd(L)Cl2] and [Ru(?4-C8H12)(L)Cl2] {where, L = thiosemicarbazones derived from 5-nitrothiophene-2-carboxaldehyde and cycloalkylaminothiocarbonyl hydrazines} have been isolated by the reaction of [Pd(DMSO)2Cl2] and [Ru(?4-C8H12)(CH3CN)2Cl2] with 5-nitrothiophene-2-carboxaldehyde thiosemicarbazones. The spectral data revealed that the thiosemicarbazones act as bidentate ligands, making use of thionic sulphur and the azomethine nitrogen atom for coordination to the central

Shailendra Singh; Neelam Bharti; Fehmida Naqvi; Amir Azam

2004-01-01

57

In vitro antioxidant properties of new thiazole derivatives  

Microsoft Academic Search

A series of novel N2-[2-chloro-4(3,4,5-trimethoxy phenyl azetidin-1-yl]-N4-(substituted aryl)-1,3-thiazole-2,4-diamine (4a–g) were synthesized starting from 3,4,5-trimethoxy benzaldehyde thiosemicarbazone (1). The compound (1) was obtained by condensing 3,4,5-trimethoxy benzaldehyde with thiosemicarbazide in methanol. 3,4,5-Trimethoxy benzaldehyde thiosemicarbazone (1) on treatment with chloracetyl chloride afforded 4-chloro-[2-(3,4,5-trimethoxy benzylidine) hydrazinyl]-1,3-thiazole (2). Compound (2) was reacted with chloracetyl chloride and triethylamine to obtain the corresponding 4-chloro-N-[2-chloro-4(3,4,5-trimethoxy phenyl) azetidin-1-yl]-1,3-thiazole-2-amine

V. Jaishree; N. Ramdas; J. Sachin; B. Ramesh

58

Microwave synthesis of mixed ligand diimine-thiosemicarbazone complexes of ruthenium(ii): biophysical reactivity and cytotoxicity†  

PubMed Central

A novel microwave-assisted synthetic method has been used to synthesise a series of mixed ligand ruthenium(ii) compounds containing diimine as well as bidentate thiosemicarbazone ligands. The compounds contain the diimine 1,10-phenanthroline (phen) or 2,2?-bipyridine (bpy) and the thiosemicarbazone is derived from 9-anthraldehyde. Based on elemental analyses and spectroscopic data, the compounds are best formulated as [(phen)2Ru(thiosemicarbazone)](PF6)2 and [(phen)2Ru(thiosemicarbazone)](PF6)2 where thiosemicarbazone = 9-anthraldehydethiosemicarbazone, 9-anthraldehyde-N(4)-methylthiosemicarbazone, and 9-anthraldehyde-N(4)-ethylthiosemicarbazone. Fluorescence competition studies with ethidium bromide, along with viscometric measurements suggests that the complexes bind calf thymus DNA (CTDNA) relatively strongly via an intercalative mode possibly involving the aromatic rings of the diimine ligands. The complexes show good cytotoxic profiles against MCF-7 and MDA-MB-231 (breast adenocarcinoma) as well as HCT 116 and HT-29 (colorectal carcinoma) cell lines.

Beckford, Floyd A.; Shaloski, Michael; Leblanc, Gabriel; Thessing, Jeffrey; Lewis-Alleyne, Lesley C.; Holder, Alvin A.; Li, Liya; Seeram, Navindra P.

2010-01-01

59

Synthesis of some new 4(3 H)-quinazolinone-2-carboxaldehyde thiosemicarbazones and their metal complexes and a study on their anticonvulsant, analgesic, cytotoxic and antimicrobial activities – Part1  

Microsoft Academic Search

Novel 3-aryl-4(3H)-quinazolinone-2-carboxaldehydes, their corresponding Schiff’s base and thiosemicarbazone derivatives were synthesized from the starting 5-iodo anthranilic acid. Copper(II), zinc(II) complexes of some thiosemicarbazone derivatives were also synthesized and characterized. Screening for some selected compounds was carried out to probe their potential anticonvulsant, analgesic, cytotoxic as well as their antimicrobial activities.

Mohsen M. Aly; Yahia A. Mohamed; Khairy A. M. El-Bayouki; Wahid M. Basyouni; Samir Y. Abbas

2010-01-01

60

Structure-function relationships for a new series of pyridine-2-carboxaldehyde thiosemicarbazones on ribonucleotide reductase activity and tumor cell growth in culture and in vivo.  

PubMed

The synthesis of a new series of pyridine-2-carboxaldehyde thiosemicarbazones (HCTs) that have amino groups in the 3- and 5-positions has allowed the comparison of the structure/function relationships with regard to inhibition of ribonucleotide reductase activity, L1210 cell growth in culture and L1210 leukemia in vivo. 3-Aminopyridine-2-carboxaldehyde thiosemicarbazones are more active than the corresponding 3-hydroxy-derivatives. The 3-amino-2-pyridine carboxaldehyde thiosemicarbazones were also more active then the 5-amino-2-carboxaldehyde thiosemicarbazones in inhibiting ribonucleotide reductase activity and L1210 cell growth in culture and in vivo. N-Acetylation of the 3-amino derivative resulted in a compound that was much less active both in vitro and in vivo; N-acetylation of the 5-amino derivative did not alter the in vitro inhibitory properties, but did eliminate the antitumor properties in vivo. When the most active HCTs were studied in more detail, it was found that the incorporation of [3H]thymidine into DNA was inhibited completely without the inhibition of [3H]uridine incorporation into RNA. Further, the conversion of [14C]cytidine to deoxycytidine nucleotides and incorporation into DNA was inhibited by the HCTs without an effect on the incorporation of cytidine into RNA. These data support the conclusion that ribonucleotide reductase is the major site of action of these HCTs. The 3-aminopyridine-2-carboxaldehyde thiosemicarbazones emerge as strong candidates for development for clinical trials in cancer patients. PMID:7572354

Cory, J G; Cory, A H; Rappa, G; Lorico, A; Liu, M C; Lin, T S; Sartorelli, A C

1995-01-01

61

2-Phenyl-tetrahydropyrimidine-4(1H)-ones - cyclic benzaldehyde aminals as precursors for functionalised ?2-amino acids  

PubMed Central

Summary Novel procedures have been developed to condense benzaldehyde effectively with ?-amino acid amides to cyclic benzyl aminals. Double carbamate protection of the heterocycle resulted in fully protected chiral ?-alanine derivatives. These serve as universal precursors for the asymmetric synthesis of functionalised ?2-amino acids containing acid-labile protected side chains. Diastereoselective alkylation of the tetrahydropyrimidinone is followed by a chemoselective two step degradation of the heterocycle to release the free ?2-amino acid. In the course of this study, an L-asparagine derivative was condensed with benzaldehyde and subsequently converted to orthogonally protected (R)-?2-homoaspartate.

Nahrwold, Markus; Stoncius, Arvydas; Penner, Anna; Neumann, Beate; Stammler, Hans-Georg

2009-01-01

62

Direct Spectrophotometric Assay for Benzaldehyde Lyase Activity  

PubMed Central

Benzaldehyde lyase from Pseudomonas fluorescens Biovar I. (BAL, EC 4.1.2.38) is a versatile catalyst for the organic synthesis of chiral ?-hydroxy ketones. To allow fast assessment of enzyme activity, a direct spectrophotometric assay is desirable. Here, a new robust and easy-to-handle assay based on UV absorption is presented. The assay developed is based on the ligation of the ?-hydroxy ketone (R)-2,2?-furoin from 2-furaldehyde. A robust assay with direct monitoring of the product is facilitated with a convenient concentration working range minimising experimental associated with low concentrations.

Natalia, Dessy; Kohlmann, Christina; Ansorge-Schumacher, Marion B.; Greiner, Lasse

2011-01-01

63

2-Bromo-5-fluoro-benzaldehyde  

PubMed Central

In the title compound, C7H4BrFO, the benzaldehyde O atom is found to be trans to the 2-bromo substituent. In the crystal, short Br?F inter­actions between the bromine and fluorine substituents are observed at distances of 3.1878?(14), 3.3641?(13) and 3.3675?(14)?Å. Offset face-to-face ?-stacking inter­actions are also observed for both of the independent mol­ecules in the asymmetric unit running parallel to the crystallographic b axis, characterized by centroid–centroid distances of 3.8699?(2) and 3.8699?(2)?Å.

Tureski, Robert E.; Tanski, Joseph M.

2013-01-01

64

Final report on the safety assessment of benzaldehyde.  

PubMed

Benzaldehyde is an aromatic aldehyde used in cosmetics as a denaturant, a flavoring agent, and as a fragrance. Currently used in only seven cosmetic products, its highest reported concentration of use was 0.5% in perfumes. Benzaldehyde is a generally regarded as safe (GRAS) food additive in the United States and is accepted as a flavoring substance in the European Union. Because Benzaldehyde rapidly metabolizes to Benzoic Acid in the skin, the available dermal irritation and sensitization data demonstrating no adverse reactions to Benzoic Acid were considered supportive of the safety of Benzaldehyde. Benzaldehyde is absorbed through skin and by the lungs, distributes to all well-perfused organs, but does not accumulate in any specific tissue type. After being metabolized to benzoic acid, conjugates are formed with glycine or glucuronic acid, and excreted in the urine. Little acute toxicity was seen. The oral LD(50) of Benzaldehyde in rats and mice ranged from 800 to 2850 mg/kg. The intraperitoneal LD(50) in white rats was 3265 mg/kg. In short-term oral studies, the no observed adverse effect level (NOAEL) was 400 mg/kg in rats and mice. In subchronic oral studies, the NOAEL was 400 mg/kg in rats and 600 mg/kg in mice. In a 16-week feeding study, rats given up to 10,000 ppm showed no signs of toxicity. Repeated inhalation of volatilized Benzaldehyde produced ocular and nasal irritation at 500 ppm and death in rabbits at 750 ppm. Undiluted Benzaldehyde was irritating to rabbit eyes, causing edema, erythema, and pain. Benzaldehyde was determined not to be a contact sensitizer, but did produce allergic reactions in a maximization test. Clinical reports of allergy to Benzaldehyde are rare. Benzoic Acid did not produce irritation or sensitization reactions in human clinical studies. Benzoic Acid also failed to produce reactions in phototoxicity and photosensitization tests. Neither Benzaldehyde, Benzoic Acid, nor Sodium Benzoate are reproductive or developmental toxicants at doses that are nontoxic to the mother. In a behavioral study, blood levels of 0.12 ng/ml Benzaldehyde produced a 44% reduction in motor activity in mice. Benzaldehyde did not produce mutations in bacterial assays, but did produce chromosomal abnormalities in Chinese hamster cells and increased mutations in a mouse lymphoma forward mutation assay. Benzaldehyde was evaluated by the National Toxicology Program, which found no evidence of carcinogenicity in rats, and some evidence of carcinogenicity in mice. Several studies have suggested that Benzaldehyde can have carcinostatic or antitumor properties. Overall, at the concentrations used in cosmetics, Benzaldehyde was not considered a carcinogenic risk to humans. Although there are limited irritation and sensitization data available for Benzaldehyde, the available dermal irritation and sensitization data and ultraviolet (UV) absorption and phototoxicity data demonstrating no adverse reactions to Benzoic Acid support the safety of Benzaldehyde as currently used in cosmetic products. PMID:16835129

Andersen, Alan

2006-01-01

65

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

PubMed

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 (Fe(2+)) in hemoglobin. This creates Fe(3+) methemoglobin that does not deliver oxygen. Fe(2+) in hemoglobin normally auto-oxidizes to inactive Fe(3+) 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. PMID:22335579

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

2012-02-01

66

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

67

Substrate-specificity of benzyl alcohol dehydrogenase and benzaldehyde dehydrogenase encoded by TOL plasmid pWW0. Metabolic and mechanistic implications.  

PubMed Central

The substrate-specificities of benzyl alcohol dehydrogenase and benzaldehyde dehydrogenase, encoded by TOL plasmid pWW0 of Pseudomonas putida mt-2, were determined. The rates of benzyl alcohol dehydrogenase-catalysed oxidation of substituted benzyl alcohols and reduction of substituted benzaldehydes were independent of the electronic nature of the substituents at positions 3 and 4. Substitutions at position 2 of benzyl alcohol affected the reactivity of benzyl alcohol dehydrogenase: the velocity of the benzyl alcohol dehydrogenase-catalysed oxidation was lower for compounds possessing electron-withdrawing substitutions. In the reverse reaction of benzyl alcohol dehydrogenase, none of the substitutions tested influenced the apparent kcat. values. The rates of benzaldehyde dehydrogenase-catalysed oxidation of substituted benzaldehydes were influenced by the electronic nature of the substitutions: electron-withdrawing groups at positions 3 and 4 favoured the oxidation of benzaldehydes. Substitution at position 2 of benzaldehyde greatly diminished the benzaldehyde dehydrogenase-catalysed oxidation. Substitution at position 2 with electron-donating groups essentially abolished reactivity, and only substitutions that were strongly electron-withdrawing, such as nitro and fluoro groups, permitted enzyme-catalysed oxidation. The influence of the electronic nature and the position of substitutions on the aromatic ring of the substrate on the velocity of the catalysed reactions provided some indications concerning the transition state during the oxidation of the substrates, and on the rate-limiting steps of the enzymes. Pseudomonas putida mt-2 containing TOL plasmid pWW0 cannot grow on toluene derivatives substituted at position 2, nor can it grow on 2-substituted benzyl alcohols or aldehydes. One of the reasons for this may be the substrate-specificities of the benzyl alcohol dehydrogenase and benzaldehyde dehydrogenase.

Shaw, J P; Schwager, F; Harayama, S

1992-01-01

68

A FACILE SYNTHESIS OF THIOSEMICARBAZIDESAND THIOSEMICARBAZONES BY THETRANSAMINATION OF 4METHYL4PHENYL3THIOSEMICARBAZIDE  

Microsoft Academic Search

Thiosemicarbazones of ?-(N)-heterocyclic ketones and aldehydes possess a broad spectrum of potentially useful chemotherapeutic activities. Thus, the antimalarial, antibacterial, and antiviral properties of this class have been explored by Klayman, et al. The antileishmanial activity of a series of acetyl ?-carboline thiosemicarbazones was recently described by Dodd and coworkers The ?-(N)-heterocyclic thiosemicarbazones act as tridentate ligands for transition metals; this

John P. Scovill

1991-01-01

69

Methemoglobin formation by triapine, di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone (Dp44mT), and other anticancer thiosemicarbazones: identification of novel thiosemicarbazones and therapeutics that prevent this effect.  

PubMed

Thiosemicarbazones are a group of compounds that have received comprehensive investigation as anticancer agents. The antitumor activity of the thiosemicarbazone, 3-amino-2-pyridinecarboxaldehyde thiosemicarbazone (3-AP; triapine), has been extensively assessed in more than 20 phase I and II clinical trials. These studies have demonstrated that 3-AP induces methemoglobin (metHb) formation and hypoxia in patients, limiting its usefulness. Considering this problem, we assessed the mechanism of metHb formation by 3-AP compared with that of more recently developed thiosemicarbazones, including di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone (Dp44mT). This was investigated using intact red blood cells (RBCs), RBC lysates, purified oxyhemoglobin, and a mouse model. The chelation of cellular labile iron with the formation of a redox-active thiosemicarbazone-iron complex was found to be crucial for oxyhemoglobin oxidation. This observation was substantiated using a thiosemicarbazone that cannot ligate iron and also by using the chelator, desferrioxamine, that forms a redox-inactive iron complex. Of significance, cellular copper chelation was not important for metHb generation in contrast to its role in preventing tumor cell proliferation. Administration of Dp44mT to mice catalyzed metHb and cardiac metmyoglobin formation. However, ascorbic acid administered together with the drug in vivo significantly decreased metHb levels, providing a potential therapeutic intervention. Moreover, we demonstrated that the structure of the thiosemicarbazone is of importance in terms of metHb generation, because the DpT analog, di-2-pyridylketone-4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC), does not induce metHb generation in vivo. Hence, DpC represents a next-generation thiosemicarbazone that possesses markedly superior properties. This investigation is important for developing more effective thiosemicarbazone treatment regimens. PMID:22508546

Quach, Patricia; Gutierrez, Elaine; Basha, Maram Talal; Kalinowski, Danuta S; Sharpe, Philip C; Lovejoy, David B; Bernhardt, Paul V; Jansson, Patric J; Richardson, Des R

2012-04-16

70

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

71

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

72

Effect of thiosemicarbazones on corrosion of steel in phosphoric acid produced by wet process  

SciTech Connect

Corrosion inhibition of steel in phosphoric acid (H{sub 3}PO{sub 4}) by thiosemicarbazide derivatives was studied using different chemical and electrochemical techniques. Protection efficiency up to 99% was obtained with small amounts (10{sup {minus}4} M) of cinnamaldehyde thiosemicarbazone (CTSCN). The order of increasing inhibition efficiency was correlated with the modification of the molecular structure of the inhibitors. Empirical kinetic relationship was obtained describing the experimental data obtained from the different compounds used in this investigation. Potentiodynamic polarization curves indicated that the compounds acted primarily as mixed-type inhibitors. Electrochemical impedance spectroscopy showed that the charge-transfer resistance increased and the capacitance of the double layer decreased with increasing the concentration of the inhibitor in the medium, confirming adsorption process mechanism. At high concentrations (>10{sup 4} M), the capacitance of the double layer leveled off since maximum double-layer thickness was attained. Kinetic-thermodynamic model and Flory-Huggins adsorption isotherm described the experimental findings. Number of active sites, binding constant, and change of free energy were computed for all inhibitors studied. Based on the inhibitor, it was found that each organic molecule replaced one or more adsorbed water molecule from the steel surface. The influence of exposure time on the performance of crotonaldehyde thiosemicarbazone (CrTSCN) was studied. Results showed that the inhibitor performed better with time and at a critical concentration of 5 x 10{sup {minus}4} M.

Khamis, E.; Ameer, M.A.; AlAndis, N.M.; Al-Senani, G.

2000-02-01

73

A New Antiviral Agent : 4-Bromo-3-methylisothiazole-5-carboxaldehyde thiosemicarbazone, M and B 7714  

Microsoft Academic Search

STIMULATED by reports of the antiviral activity of some thiosemicarbazones1, and particularly of the activity against neurovaccinia of isatin beta-thiosemicarbazone2,3, we sought to enhance the activity of these compounds by structural modification. Thus we synthesized N-ethylisatin beta-thiosemicarbazone independently of, but somewhat later than, Bauer and Sadler4. At the same time, we had been making a systematic study of the chemistry

R. Slack; K. R. H. Wooldridge; J. A. McFadzean; S. Squires

1964-01-01

74

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

2009-03-11

75

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

76

Biomass pyrolysis: Thermal decomposition mechanisms of furfural and benzaldehyde  

NASA Astrophysics Data System (ADS)

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.

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

2013-09-01

77

Photocatalytic oxidation of toluene to benzaldehyde by molecular oxygen  

SciTech Connect

The visible light irradiation of aqueous solutions containing toluene, uranyl(VI) ions, and O{sub 2} results in the formation of benzaldehyde as a major product. Small amounts of PhCH{sub 2}OH are also formed. The yields of benzaldehyde are 3 times greater for toluene-h{sub 8} than for toluene-d{sub 8}, but the kinetic isotope effect for the quenching of the excited state {sup *}UO{sub 2}{sup 2+} by toluene is negligible (k{sub toluene-h(8)}/k{sub toluene-d(8)}=1.2). This and other evidence indicate that the quenching takes place in two parallel pathways. The major one involves the aromatic portion of tolune and leads to the recovery of the reactants. The minor, productive path takes place by hydrogen atom abstraction from the methyl group, followed by the oxidation of PhCH{sub 2}{sup {center_dot}}. Cumene, benzyl alcohol, and benzaldehyde react similarly. 31 refs., 5 figs., 1 tab.

Mao, Y.; Bakac, A. [Ames LAb., IA (United States)]|[Iowa State Univ., Ames, IA (United States)

1996-03-07

78

Synthesis and characterization of some new Cu(II), Ni(II) and Zn(II) complexes with salicylidene thiosemicarbazones: antibacterial, antifungal and in vitro antileukemia activity.  

PubMed

Thirty two new Cu(II), Ni(II) and Zn(II) complexes (1-32) with salicylidene thiosemicarbazones (H?L¹-H?L¹?) were synthesized. Salicylidene thiosemicarbazones, of general formula (X)N-NH-C(S)-NH(Y), were prepared through the condensation reaction of 2-hydroxybenzaldehyde and its derivatives (X) with thiosemicarbazide or 4-phenylthiosemicarbazide (Y = H, C6H5). The characterization of the new formed compounds was done by ¹H-NMR, ¹³C-NMR, IR spectroscopy, elemental analysis, magnetochemical, thermoanalytical and molar conductance measurements. In addition, the structure of the complex 5 has been determined by X-ray diffraction method. All ligands and metal complexes were tested as inhibitors of human leukemia (HL-60) cells growth and antibacterial and antifungal activities. PMID:23887722

Pahontu, Elena; Fala, Valeriu; Gulea, Aurelian; Poirier, Donald; Tapcov, Victor; Rosu, Tudor

2013-07-24

79

Transition metal quinone–thiosemicarbazone complexes 3: Spectroscopic characterizations of spin-mixed iron (III) of naphthoquinone–thiosemicarbazones  

Microsoft Academic Search

An interesting series of iron (III) complexes with naphthoquinone–thiosemicarbazones are synthesized and physico-chemically characterized by elemental analysis, UV–vis, IR, EPR and magnetic susceptibility measurements. They possess a cationic octahedral [FeL2]+ species and a tetrahedral [FeCl4]? anion and exhibit unusual spin-mixed states involving high-spin and low-spin ferric centers as revealed from magnetic behavior with significant amount of exchange interactions mediated by

Rajeev C. Chikate; Subhash B. Padhye

2007-01-01

80

A 119Sn Mössbauer Study of Tin(IV) Complexes of 2- and 4-Benzoylpyridine Thiosemicarbazone and 4-Benzoylpyridine Semicarbazone  

NASA Astrophysics Data System (ADS)

A 119Sn Mössbauer study was carried out of tin(IV) complexes with 2-benzoylpyridine thiosemicarbazone (H2Bz4DH) and its N(4)-methyl (H2Bz4M) and N(4)-phenyl (H2Bz4Ph) derivatives: [Sn(2Bz4DH)Cl3] (1), [Sn(2Bz4DH)PhCl2] (2), [Sn(2Bz4M)Cl3] (3), [H22Bz4M]2[Ph2SnCl4] (4), [Sn(2Bz4Ph)PhCl2] (5), [Sn(2Bz4Ph)Ph2Cl] (6), in which H2Bz4R stands for the neutral ligand and 2Bz4R stands for the anionic thiosemicarbazone. In addition, 119Sn Mössbauer studies of the tin(IV) complexes [Sn(H4Bz4DH)2Cl4H2O] (7), [Sn(H4BzPS)2Cl4H2O] (8) with 4-benzoylpyridine thiosemicarbazone (H4Bz4DH) and the correspondent semicarbazone (H4BzPS) were performed. The isomer shifts decrease upon coordination due to the variation in the percentage of s character as tin changes from approximately sp3 hybridization in the tin salts to sp3d2 in the octahedral or sp3d3 in the heptahedral complexes. The Mössbauer parameters of compound (4) showed the existence of two tin(IV) sites, which have been attributed to the presence of the cis and trans isomers.

Pérez-Rebolledo, Anayive; Ardisson, José D.; de Lima, Geraldo M.; Macedo, Waldemar A. A.; Beraldo, Heloisa

2005-06-01

81

Direct synthesis of pterocarpans via aldol condensation of phenylacetates with benzaldehydes  

Microsoft Academic Search

Aldol condensation between phenylacetates and benzaldehydes affords 2,3-diaryl-3-hydroxypropanoates which are converted into pterocarpans via stepwise deprotection and cyclization in moderate to high yields.

Theunis G. van Aardt; Hendrik van Rensburg; Daneel Ferreira

1999-01-01

82

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

PubMed Central

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)](PF6)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 104 M?1. They are also strong binders of human serum albumin having binding constants on the order of 104 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 IC50 values range from 7 – 159 ?M (after 72 h drug incubation). They also have antibacterial activity against Gram-positive strains of pathogenic bacteria with IC50 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; Mbarushimana, P. Canisius; Brock, Alyssa; Didion, Jacob; Woods, Jason; Gonzalez-Sarrias, Antonio; Seeram, Navindra P.

2011-01-01

83

Use of thiosemicarbazone and para-nitrobenzoic acid in screening tests for anonymous mycobacteria  

PubMed Central

In screening for anonymous mycobacteria the use of thiosemicarbazone (10?g./ml.) may give rise to false positive results. Although these can usually be overcome by further tests, additional time and effort is required, which seriously limits the value of thiosemicarbazone as a true screening agent. Para-nitrobenzoic acid (500 ?g./ml.) has proved more satisfactory in our hands; no false positive results have been obtained and it has the additional advantage that strains of M. kansasii (usually thiosemicarbazone sensitive) are resistant to para-nitrobenzoic acid.

Barrie, John D.

1967-01-01

84

Complexes of 2-acetyl-?-butyrolactone and 2-furancarbaldehyde thiosemicarbazones: Antibacterial and antifungal activity  

Microsoft Academic Search

Cobalt, nickel, copper and zinc coordination compounds of two thiosemicarbazones with general composition ML2 (L: monodeprotonated ligand corresponding to 2-acetyl-?-butyrolactone thiosemicarbazone, HL1, and 2-furancarbaldehyde thiosemicarbazone, HL2) and also complexes with general composition MCl2(HL2) were synthesized (except [NiCl2(HL2)] and [Co(L2)2]). The interaction of CuCl2 with HL2 gave [CuCl(HL2)], a copper(I) complex. The ligands and metal complexes were characterized by IR, 1H

María C. Rodríguez-Argüelles; Patricia Tourón-Touceda; Roberto Cao; Ana M. García-Deibe; Paolo Pelagatti; Corrado Pelizzi; Franca Zani

2009-01-01

85

Reinvestigation of growth of urea thiosemicarbazone monohydrate crystal  

NASA Astrophysics Data System (ADS)

The reaction of urea with thiosemicarbazide in 1:1 mole ratio in aqueous solution does not result in the formation of urea thiosemicarbazone monohydrate crystal, as reported by Hanumantharao, Kalainathan and Bhagavannarayana [Spectrochim. Acta A91 (2012) 345-351]. A reinvestigation of the reported reaction reveals that the crystal obtained is the starting material namely thiosemicarbazide, which has been unambiguously confirmed with the aid of infrared and 1H NMR spectra and single crystal X-ray structure determination. Analysis of 1H NMR spectrum reveals that thiosemicarbazide exhibits thione-thiol tautomerism in solution. In contrast, thiosemicarbazide exists as the thione tautomer in the solid state.

Srinivasan, Bikshandarkoil R.; Raghavaiah, Pallepogu; Nadkarni, V. S.

2013-08-01

86

Inner-shell spectroscopy of benzaldehyde, terephthalaldehyde, ethyl benzoate, terephthaloyl chloride, and phosgene: Models for core excitation of poly(ethylene terephthalate)  

Microsoft Academic Search

Oscillator strengths for C 1s and O 1s excitation of terephthalaldehyde, benzaldehyde, and ethyl benzoate and C 1s, O 1s and Cl 2p excitation of terephthaloyl chloride and phosgene have been derived from electron energy loss spectra recorded under scattering conditions where electric dipole transitions dominate. Extended Hueckel molecular orbital (EHMO) calculations were used to aid interpretation of the core

A. P. Hitchcock; S. G. Urquhart; E. G. Rightor

1992-01-01

87

Inactivation and inhibition of Rous sarcoma virus by copper-binding ligands: thiosemicarbazones, 8-hydroxyquinolines, and isonicotinic acid hydrazide.  

PubMed

We have shown that three types of copper-binding ligands, thiosemicarbazones, 8-hydroxyquinolines, and isonicotinic acid hydrazide and their copper complexes, inactivate the transforming ability of RSV and inhibit its RNA-dependent DNA polymerases. Three other compounds, 2-pyridine thiosemicarbazone, 1-formyl isoquinoline thiosemicarbazone, and diphenyl thiocarbazone inhibit transformation by RSV intracellularly. Most but not all of these compounds bind to nucleic acids in the presence of copper, which may be important in their mode of action. PMID:81642

Levinson, W; Rohde, W; Mikelens, P; Jackson, J; Antony, A; Ramakrishnan, T

1977-03-01

88

Deposition of rod-shaped antimony sulfide thin films from single-source antimony thiosemicarbazone precursors  

Microsoft Academic Search

Antimony sulfide thin films were deposited on glass substrates by aerosol assisted chemical vapour deposition technique using single source precursors, namely, antimony(III) thiosemicarbazones, SbCl3(L) (L = thiosemicarbazones of thiophene-2-carboxaldehyde (1) and cinnamaldehyde (2)). The deposited films were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray analysis and UV–visible spectroscopy in order to identify their phases, morphologies, compositions and

Jasmine B. Biswal; Narayan V. Sawant; Shivram S. Garje

2010-01-01

89

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

90

Synthesis of Hydroxyl Radical Scavengers from Benzalacetone and its Derivatives  

Microsoft Academic Search

Synthesis of hydroxyl radical scavengers from benzalacetone and its derivatives has been done. Benzalacetone synthesis was done by crossed aldol condensation between benzaldehyde and acetone with 1:1 mol ratio, while dibenzalacetone in 2:1 mol ratio. Benzalacetone derivatives were synthesized by replacing benzaldehyde with its derivatives, i.e. p-anisaldehyde, veratraldehyde and cinnamaldehyde. The compounds that were active as radical scavengers based on

Sri Handayani; Indyah Sulistyo Arty

2008-01-01

91

Time-dependent conversion of benzyl alcohol to benzaldehyde and benzoic acid in aqueous solutions  

Microsoft Academic Search

The oxidative reaction: benzyl alcohol–benzaldehyde–benzoic acid was investigated in time in aqueous solutions of benzyl alcohol widely used as a preservative in medicine and cosmetology. The solutions of benzyl alcohol were stored at concentrations from 0.005 to 2.09mg\\/ml for a long time under different conditions. The presence of benzaldehyde and benzoic acid in these solutions was controlled by liquid chromatography

N. N. Sudareva; E. V. Chubarova

2006-01-01

92

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

Microsoft Academic Search

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

David Tsui; Derek van der Kooy

2008-01-01

93

Novel iron carbonyl complexes from thiophene-2-carboxaldehyde thiosemicarbazone  

Microsoft Academic Search

The reaction of thiophene-2-carboxaldehyde thiosemicarbazone (2-C4H3SCHNNHC(S)NH2) (1) with diiron nonacarbonyl under mild conditions in anhydrous benzene yields three iron carbonyl organometallic clusters: (i) Fe2S2 square-base pyramidal cluster 2 ([Fe(CO)3]3(?3-S)2), (ii) Fe2S2 square-base pyramidal metal carbene cluster 3 ([Fe(CO)3]2Fe(CO)2(?3-S)2(C(NH2)NHNCH (2-C4H3S)), and (iii) double butterfly cluster 4 ([Fe(CO)3]3Fe(CO)2(?4-S)(C,N; C(NH2)NHNCH(2-C4H3S) (?2-S, N; SC(NH2)NNCH(2-C4H3S)), and an octahedral complex 5 (Fe(CO)2(S, N; SC(NH2)NNCH (2-C4H3S))2. These

Wen-Shyan Hong; Chih-Yu Wu; Chen-Shiang Lee; Wen-Shu Hwang; Michael Y Chiang

2004-01-01

94

Kinetics and mechanism of the oxidation of substituted benzaldehydes by benzyltrimethylammonium chlorobromate  

PubMed

The oxidation of 35 monosubstituted benzaldehydes by benzyltrimethylammonium chlorobromate (BTMACB) in aqueous acetic acid leads to the formation of the corresponding benzoic acids. The reaction is first order with respect to both benzaldehyde and BTMACB. The reaction failed to induce the polymerization of acrylonitrile. There is no effect of benzyltrimethylammonium chloride or potassium bromide on the reaction rate. The oxidation of [(2)H]benzaldehyde (PhCDO) indicated the presence of a substantial kinetic isotope effect. The effect of solvent composition indicated that the reaction rate increases with an increase in the polarity of the solvent. The rates of oxidation of meta- and para-substituted benzaldehydes were correlated in terms of Charton's triparametric LDR equation, whereas the oxidation of ortho-substituted benzaldehydes was correlated with the tetraparametric LDRS equation. The oxidation of para-substituted benzaldehydes is more susceptible to the delocalization effect, whereas the oxidation of ortho-and meta-substituted compounds displayed a greater dependence on the field effect. The positive value of eta suggests the presence of an electron-deficient reaction center in the rate-determining step. The reaction is subjected to steric hindrance by the ortho substituents. PMID:10843612

Raju; Sharma; Banerji

2000-06-01

95

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

96

Toxicological, toxicokinetic and gastroprotective evaluation of the benzaldehyde semicarbazone.  

PubMed

Benzaldehyde semicarbazone (BS) has presented positive results in several pharmacological models, including anticonvulsivant and anti-inflammatory models. The present study evaluated the preclinical toxicity (acute and subchronic), as well as the toxicokinetic and gastroprotective effects of BS against ethanol lesions. Oral doses of 300 and 2000mg/kg were used in the preclinical acute toxicity study; 100, 200, and 300mg/kg were used in both the subchronic toxicity evaluation and the gastric study; and 300mg/kg was used in the toxicokinetic study. No impact from the dose of 300mg/kg could be identified; while, one animal died at 2000mg/kg in the acute toxicity test. In the subchronic toxicity test, changes in the biochemical parameters of the liver, as well as in the histopatological evaluation, demonstrated that BS is a hepatotoxic drug. BS proved to be effective for moderate and severe gastric lesions. In the toxicokinetics study, BS presented a low concentration and rapid plasma disappearance. Several results also indicate that BS is likely to be mostly eliminated from the liver and may well undergo a first-pass effect after oral absorption. It was impossible to estimate the noobserved-adverse-effect-levels (NOAEL) and lowest-observed-adverse-effect-levels (LOAEL) due to the presence of hepatotoxicity in all tested doses. PMID:23391596

Vieira, A E D; Araujo, G L; Galassi, C M; Rodrigues, R F; Cassalli, G D; Kaiser, M; Dalla Costa, T; Beraldo, H; Tagliati, C A

2013-02-04

97

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

98

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

99

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

2013-05-20

100

Synthesis, structural and thermal studies of some biologically active antimony semicarbazones and thiosemicarbazones  

Microsoft Academic Search

The reactions of Ph3SbCl2 and SbCl3 with semicarbazone and thiosemicarbazone ligands resulted in Ph3SbCl2(L) and SbCl3(L) (L?=?semicarbazone and thiosemicarbazone ligands). These complexes were characterized by elemental analyses, IR, H and C {H} NMR spectral data, and conductometric measurements. On the basis of spectroscopic data, a seven-coordinate and a five-coordinate antimony with ligand coordination through oxygen\\/sulfur and azomethine nitrogen have been

Narayan V. Sawant; Jasmine B. Biswal; Shivram S. Garje

2011-01-01

101

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

102

?-Cyclodextrin hydrogels for the ocular release of antibacterial thiosemicarbazones.  

PubMed

Two types of hydrophilic networks with conjugated beta-cyclodextrin (?-CD) were developed with the aim of engineering useful platforms for the localized release of an antimicrobial 5,6-dimethoxy-1-indanone N4-allyl thiosemicarbazone (TSC) in the eye and its potential application in ophthalmic diseases. Poly(2-hydroxyethyl methacrylate) soft contact lenses (SCLs) displaying ?-CD, namely pHEMA-co-?-CD, and super-hydrophilic hydrogels (SHHs) of directly cross-linked hydroxypropyl-?-CD were synthesized and characterized regarding their structure (ATR/FT-IR), drug loading capacity, swelling and in vitro release in artificial lacrimal fluid. Incorporation of TSC to the networks was carried out both during polymerization (DP method) and after synthesis (PP method). The first method led to similar drug loads in all the hydrogels, with minor drug loss during the washing steps to remove unreacted monomers, while the second method evidenced the influence of structural parameters on the loading efficiency (proportion of CD units, mesh size, swelling degree). Both systems provided a controlled TSC release for at least two weeks, TSC concentrations (up to 4000?g/g dry hydrogel) being within an optimal therapeutic window for the antimicrobial ocular treatment. Microbiological tests against P. aeruginosa and S. aureus confirmed the ability of TSC-loaded pHEMA-co-?-CD network to inhibit bacterial growth. PMID:23499082

Glisoni, Romina J; García-Fernández, María J; Pino, Marylú; Gutkind, Gabriel; Moglioni, Albertina G; Alvarez-Lorenzo, Carmen; Concheiro, Angel; Sosnik, Alejandro

2012-12-24

103

The photochemical reaction of excited acetophenone and benzaldehyde in the gas phase  

NASA Astrophysics Data System (ADS)

The photochemistry of acetophenone and benzaldehyde with hydrogen donors has been studied in the gas phase. The quenching rate constants of the triplet acetophenone and benzaldehyde can be well correlated with the ionization potentials of hydrogen donors. The results suggested that the charge-transfer interaction plays an important role in the gas-phase reaction as in the case of condensed phase reaction. The slopes of Rehm-Weller plot are more stiff in the gas-phase reaction than condensed phase reaction, which indicates higher degree of charge transfer. Secondary amines were consistently better quencher of carbonyl triplet than tertiary amines, and steric effects are probably to be of importance.

Matsushita, Yoshihisa; Yamaguchi, Yoshitaka; Hikida, Takumi

1996-12-01

104

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

105

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

106

Acenaphthenequinone thiosemicarbazone and its transition metal complexes: Synthesis, structure, and biological activity  

Microsoft Academic Search

The reaction of iron, nickel, copper, and zinc chlorides or acetates with acenaphthenequinone thiosemicarbazone, Haqtsc leads to the formation of novel complexes that have been characterized by spectroscopic studies (NMR, IR) and biological properties. The crystal structures of the free ligand Haqtsc 1 and of the compound [Ni(aqtsc)2] · DMF 2, have also been determined by X-ray methods from diffractometer

Maria C Rodriguez-Argüelles; Marisa Belicchi Ferrari; Giovanna Gasparri Fava; Corrado Pelizzi; Giorgio Pelosi; Roberto Albertini; Antonio Bonati; Pier Paolo Dall'Aglio; Paolo Lunghi; Silvana Pinelli

1997-01-01

107

In vitro and in vivo evaluation of isatin-?-thiosemicarbazone and marboran against vaccinia and cowpox virus infections  

Microsoft Academic Search

It has been reported previously that some thiosemicarbazone compounds have prophylactic activity against smallpox disease and therapeutic activity against vaccinia virus (VV) infections. In these studies, isatin-?-thiosemicarbazone (IBT) and marboran were administered once daily by intraperitoneal (ip) injection to mice using 30, 10 or 3mg\\/kg for 5 days beginning 24, 48 or 72h after inoculation with VV or cowpox virus

Debra C. Quenelle; Kathy A. Keith; Earl R. Kern

2006-01-01

108

Studies of the Antineoplastic Activity and Metabolism of a-(\\/V)Heterocyclic Carboxaldehyde Thiosemicarbazones in Dogs and Mice1  

Microsoft Academic Search

SUMMARY The antineoplastic effects of a-(\\/V)-heterocyclic Carboxaldehyde thiosemicarbazones were studied in dogs with lymphosarcoma, and some of their metabolic features were studied in both mice and dogs. Significant regression (38 to 72%) of tumor masses occurred in dogs treated with i.v. doses of 2 to 6 mg of the sodium salt of 1-formylisoquinoline thiosemicarbazone per kg for a maximum of

William A. Creasey; Krishna C. Agrawal; Robert L. Capizzi; Kenneth K. Stinson; Alan C. Sartorelli

109

Ribonucleotide reductase inhibition by metal complexes of Triapine (3-aminopyridine-2-carboxaldehyde thiosemicarbazone): A combined experimental and theoretical study  

Microsoft Academic Search

Triapine (3-aminopyridine-2-carboxaldehyde thiosemicarbazone, 3-AP) is currently the most promising chemotherapeutic compound among the class of ?-N-heterocyclic thiosemicarbazones. Here we report further insights into the mechanism(s) of anticancer drug activity and inhibition of mouse ribonucleotide reductase (RNR) by Triapine. In addition to the metal-free ligand, its iron(III), gallium(III), zinc(II) and copper(II) complexes were studied, aiming to correlate their cytotoxic activities with

Ana Popovi?-Bijeli?; Christian R. Kowol; Maria E. S. Lind; Jinghui Luo; Fahmi Himo; Éva A. Enyedy; Vladimir B. Arion; Astrid Gräslund

2011-01-01

110

Serotonin Mediates a Learned Increase in Attraction to High Concentrations of Benzaldehyde in Aged "C. elegans"  

ERIC Educational Resources Information Center

|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…

Tsui, David; van der Kooy, Derek

2008-01-01

111

On the Condensation of Phenylnitromethane with Benzaldehyde: On Cis- and Trans-7-Nitro Stilbene.  

National Technical Information Service (NTIS)

Benzaldehyde and phenylnitromethane were condensed using aliphatic bases and obtained 7-nitro stilbene (benzylide phenyl nitromethant) at melting point 75 deg with a yield of 60 to 70 percent of the theory. In addition to the pale yellow 7-nitro stilbene ...

F. Heim

1975-01-01

112

Serotonin Mediates a Learned Increase in Attraction to High Concentrations of Benzaldehyde in Aged "C. elegans"  

ERIC Educational Resources Information Center

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…

Tsui, David; van der Kooy, Derek

2008-01-01

113

Chemo-sensitization of fungal pathogens to antimicrobial agents using benzaldehyde analogs  

Technology Transfer Automated Retrieval System (TEKTRAN)

Activity of conventional antifungal agents, fludioxonil, strobilurin and antimycinA, which target the oxidative and osmotic stress response systems, was elevated by co-application of certain analogs of benzaldehyde. Fungal tolerance to 2,3-dihydroxybenzaldehyde or 2,3-dihydroxybenzoic acid was foun...

114

Antifungal activity of redox-active benzaldehydes that target cellular antioxidation  

Technology Transfer Automated Retrieval System (TEKTRAN)

Many pathogenic fungi are becoming resistant to currently available drugs. Disruption of cellular antioxidation systems should be an effective method for control of fungal pathogens. Such disruption can be achieved with redox-active compounds. The aim of this study was to identify benzaldehydes that...

115

Synthesis, characterization antibacterial and antiproliferative activity of novel Cu(II) and Pd(II) complexes with 2-hydroxy-8-R-tricyclo[7.3.1.0. 2,7]tridecane-13-one thiosemicarbazone  

Microsoft Academic Search

Synthesis and biological activity investigation of complex compounds of Cu(II) are challenging issues because of the metal is not a xenobiotic one and the activity of ligands could be modulated by complexation. Complex combinations of Cu(II) and Pd(II) with thiosemicarbazone derivatives of 2-hydroxy-8-R-tricyclo[7.3.1.0.2,7]tridecane-13-one (where R=C3H7, C4H3O) were synthesized. The characterization of the ligands and the newly formed compounds was done

Tudor Rosu; Elena Pahontu; Simona Pasculescu; Rodica Georgescu; Nicolae Stanica; Adelina Curaj; Alexandra Popescu; Mircea Leabu

2010-01-01

116

Utility of silicon tetrafluoride as a catalyst of reactions with xenon difluoride: fluorinations of phenyl alkenes and benzaldehydes  

Microsoft Academic Search

Application of silicon tetrafluoride to fluorinations with xenon difluoride as a catalyst is investigated. It was found that vic-difluorination of phenyl alkenes and transformation of benzaldehydes to difluoromethoxybenzenes using xenon difluoride are enhanced by silicon tetrafluoride.

Masanori Tamura; Toshiyuki Takagi; Heng-dao Quan; Akira Sekiya

1999-01-01

117

Rationalization of physicochemical characters of oxazolyl thiosemicarbazone analogs towards multi-drug resistant tuberculosis: a QSAR approach.  

PubMed

The emergence of multi-drug resistant (MDR) strains of Mycobacterium tuberculosis and the continuing pandemic of tuberculosis emphasizes the urgent need for the development of new and potent anti-tubercular agents. In an effort to develop new and more effective agents to treat tuberculosis emphasis was focused on quantification of structure-activity relationship of oxazolyl thiosemicarbazone derivatives. The de novo analysis gave insight to some important structural features i.e. nitro group on phenyl ring at R(1) position is optimal for the activity and might be responsible for electronic interaction, while phenyl ring at R position interact with the hydrophobic pocket more effectively as compared to unsubstituted or methyl substituted analogs. Hansch approach offered the understanding and parameterization of interactions of the inhibitor with receptor. Similarly QSAR analysis gave some important physicochemical properties, i.e. empirical aromatic index (ARR) and 3D-MoRSE code value of scattering angle at 8A(-1). These two physicochemical properties shall be helpful in the development of more potent analogs. PMID:17343958

Gupta, Revathi A; Gupta, Arun K; Soni, Love K; Kaskhedikar, S G

2007-01-27

118

Thiosemicarbazone Complexes of Ruthenium(II) and Rhodium(I) Containing Triphenylphosphine  

Microsoft Academic Search

Several new hexa-coordinated ruthenium(II) and penta-coordinated rhodium(I) complexes of the types [RuCl(CO)(PPh3)2(TSC)], [RuH(CO)(PPh3)2(TSC)], and [Rh(PPh3)3(TSC)] (where TSC = anion of thiosemicarbazone Schiff bases) have been prepared by the reactions of [RuHCl(CO)(PPh3)3], [RuH2(CO)(PPh3)3)], and [RhH(PPh3)4] with thiosemicarbazones of 2-furaldehyde (H-FTSC), thiophene-2-carboxaldehyde (H-TCTSC), p-anisaldehyde (H-ATSC), piperonaldehyde (H-PTSC), and cyclohexanone (H-CTSC). All the new complexes obtained have been characterized on the basis of

G. Muthusamy; P. Viswanathamurthi; M. Muthukumar; K. Natarajan

2009-01-01

119

Synthesis and Fluorescent Properties of End-Functional PSt Initiated by 5-Chloromethyl-2-methoxy-benzaldehyde via ATRP  

Microsoft Academic Search

Atom transfer radical polymerization (ATRP) of styrene (St) using two initiators with similar structures, 5-chloromethyl-2-methoxy-benzaldehyde (CMMB) and 5-chloromethyl-2-hydroxyl-benzaldehyde (CMOB), CuCl\\/N,N,N?,N?,N?-pentamethyldiethyltriamine (PMDETA) as catalyst were studied in this paper. At the same reaction condition, the ATRP using CMMB was obviously accelerated, the efficiency of the initiator was higher and even could proceed at relatively lower temperature (40 °C), while ATRP using

Qing-Feng Xu; Jian-Mei Lu; Zhen Yang; Xue-Wei Xia; Li-Hua Wang

2007-01-01

120

Spectroscopic and thermodynamic studies of complexation of some divalent metal ions with isatin- ? -thiosemicarbazone  

Microsoft Academic Search

Metal complexes of some divalent metal ions (Co, Ni, Cu, Zn, Hg, and Pd) with isatin-?-thiosemicarbazone (ITS) as the Schiff base have been investigated potentiometrically and spectrophotometrically. The dissociation\\u000a constants of the ligand and formation constants of the metal complexes, as well as the corresponding thermodynamic functions\\u000a (?G, ?H and ?S) have been determined at different temperatures in ethanol—water solution.

S. S. Konstantinovi?; B. C. Radovanovi?; Z. B. Todorovi?; S. B. Ili?; B. V. Konstantinovi?

2007-01-01

121

Pyridoxal thiosemicarbazonate monohydrate of dimethylthallium(III): X-ray structure and spectroscopic properties  

Microsoft Academic Search

The title compoud, [TlMe2(HL)(H2O)] (HL = monoanion of pyridoxal thiosemicarbazone), crystallizers in the triclinic space group P1 (C1,1, No. 2). The HL?anion coordinates to the thallium atom, in an unusual mode through the S atom (Tl-S = 2.832(1) A?), and also forms a weak bond with the metal atom of a neighbouring molecule to make an asymmetric bridge (Tl?…S =

José S. Casas; Eduardo E. Castellano; María C. Rodríguez-Argüelles; Agustín Sánchez; José Sordo; Julio Zukerman-Schpector

1997-01-01

122

SYNTHESIS, CHARACTERIZATION, AND ANTITUMOR ACTIVITY OF SOME TRIVALENT LANTHANIDE COMPLEXS WITH 2-FORMYLPHENOXYACETIC ACID THIOSEMICARBAZONE  

Microsoft Academic Search

Some trivalent lanthanide complexes of the type [Ln(FAT)3]·2H2O, where Ln=La, Ce, Pr, Nd, Sm, Eu, HFAT=2-formylphenoxyacetic acid thiosemicarbazone, have been synthesized. The data of elemental analyses, IR, UV, H NMR and high resolution mass spectra show that the ligand coordinates to the metal ion via --CN7, -O- and -COO groups in the molar ratio of 3:1. All complexes are insoluble

Xinping Yang; Penfei Xu; Qingxiang Gao; Minyu Tan

2002-01-01

123

Two diphosphonate-functionalized asymmetric polyoxomolybdates with catalytic activity for oxidation of benzyl alcohol to benzaldehyde.  

PubMed

Two asymmetric polyoxomolybdates Na(6){Mo(2)O(5)[(Mo(2)O(6))NH(3)CH(2)CH(2)CH(2)C(O)(PO(3))(2)](2)}·16H(2)O (1) and (NH(4))(7)Na{MoO(2)[(Mo(2)O(6))NH(3)CH(2)CH(2)CH(2)C(O)(PO(3))(2)]}(4)·H(2)O (2) have been synthesized by the reactions of alendronic acid with molybdate. Structure analysis revealed that the polyoxoanions 1 and 2 can be described as dimeric and tetrameric aggregates of the {MoO(3)[(Mo(2)O(6))NH(3)CH(2)CH(2)CH(2)C(O)(PO(3))(2)]} units respectively. Their tetrabutylammonium salts show efficient selective oxidation of benzyl alcohol to benzaldehyde with 72.5% and 81.5% benzyl alcohol conversion, and 87.1% and 82.4% benzaldehyde selectivity, respectively. PMID:21773601

Tan, Huaqiao; Chen, Weilin; Liu, Ding; Feng, Xiaojia; Li, Yangguang; Yan, Aixue; Wang, Enbo

2011-07-19

124

4-(Dimethyl-amino)-benzaldehyde-2,4-di-nitro-aniline (1/1)  

PubMed Central

The asymmetric unit of the title compound, C9H11NO·C6H5N3O4, contains two independent mol­ecules each of 4-(dimethyl­amino)­benzaldehyde and 2,4-dinitro­aniline. In the crystal, the components are linked by inter­molecular N—H?O hydrogen bonds to form one-dimensional chains along [10]. Intra­molecular N—H?O hydrogen bonds are also present.

Zhu, Ruitao; Li, Haoyang; Zhang, Yuewen

2011-01-01

125

Antifungal activity of redox-active benzaldehydes that target cellular antioxidation  

Microsoft Academic Search

Background  Disruption of cellular antioxidation systems should be an effective method for control of fungal pathogens. Such disruption\\u000a can be achieved with redox-active compounds. Natural phenolic compounds can serve as potent redox cyclers that inhibit microbial\\u000a growth through destabilization of cellular redox homeostasis and\\/or antioxidation systems. The aim of this study was to identify\\u000a benzaldehydes that disrupt the fungal antioxidation system.

Jong H Kim; Kathleen L Chan; Noreen Mahoney; Bruce C Campbell

2011-01-01

126

Growth and morphology of the nonlinear optical crystal 3-methoxy-4-hydroxy-benzaldehyde (MHBA)  

Microsoft Academic Search

3-methoxy-4-hydroxy-benzaldehyde (MHBA) is one of the new organic materials that has become important for nonlinear optics in recent years because of its large second order nonlinear optical susceptibility and good blue transparency. Single crystals of MHBA were grown by a modified solution growth method. A study has been performed to select a suitable solvent for the growth of this material

Leroy Salary; Ravindra B. Lal; Wen Shan Wang; Manmohan D. Aggarwal; Benjamin G. Penn

1999-01-01

127

Knoevenagel condensation reaction between benzaldehyde and ethyl acetoacetate in microreactor and membrane microreactor  

Microsoft Academic Search

The Knoevenagel condensation reaction between benzaldehyde and ethyl acetoacetate was performed in microreactor using Cs-exchanged NaX catalyst and NaA membrane. The laminar flow and slow diffusion of the bulky product molecules in the microchannel resulted in the further reactions of the main Knoevenagel condensation product, 2-acetyl-3-phenylacrylic acid ethyl ester that led to byproduct formation and poorer reaction selectivity. Replacing the

W. N. Lau; K. L. Yeung; R. Martin-Aranda

2008-01-01

128

Complexes of 2-acetyl-gamma-butyrolactone and 2-furancarbaldehyde thiosemicarbazones: antibacterial and antifungal activity.  

PubMed

Cobalt, nickel, copper and zinc coordination compounds of two thiosemicarbazones with general composition ML(2) (L: monodeprotonated ligand corresponding to 2-acetyl-gamma-butyrolactone thiosemicarbazone, HL(1), and 2-furancarbaldehyde thiosemicarbazone, HL(2)) and also complexes with general composition MCl(2)(HL(2)) were synthesized (except [NiCl(2)(HL(2))] and [Co(L(2))(2)]). The interaction of CuCl(2) with HL(2) gave [CuCl(HL(2))], a copper(I) complex. The ligands and metal complexes were characterized by IR, (1)H and (13)C NMR spectroscopy, and magnetic susceptibility measurements. The crystal structure of [Ni(L(2))(2)]x 2dmso was determined and a trans-square planar coordination of the two kappa(2)-N,S chelate rings forming polymeric strips through H-bonds with dmso was observed. Actually, in all the reported complexes both ligands behaved as kappa(2)-N,S chelates, except in the case of [Co(L(1))(2)] in which HL(1) is tridentate kappa(3)-N,S,O. The antimicrobial properties of all compounds were studied using a wide spectrum of bacterial and fungal strains. The copper complexes of HL(2) were the most active against all strains, including dermatophytes and phytopathogenic fungi. Most of the studied compounds, especially [Cu(L(1))(2)], presented good activity against Haemophilus influenzae, a very harmful bacterium to humans. PMID:18947878

Rodríguez-Argüelles, María C; Tourón-Touceda, Patricia; Cao, Roberto; García-Deibe, Ana M; Pelagatti, Paolo; Pelizzi, Corrado; Zani, Franca

2008-09-11

129

Synthesis, activity and pharmacophore development for isatin-?-thiosemicarbazones with selective activity towards multidrug resistant cellsa  

PubMed Central

We have recently identified a new class of compounds that selectively kill cells that express P-glycoprotein (P-gp, MDR1), the ATPase efflux pump that confers multidrug resistance on cancer cells. Several isatin-?-thiosemicarbazones from our initial study have been validated, and a range of analogs synthesized and tested. A number demonstrated improved MDR1-selective activity over the lead, NSC73306 (1). Pharmacophores for cytotoxicity and MDR1-selectivity were generated to delineate the structural features required for activity. The MDR1-selective pharmacophore highlights the importance of aromatic/hydrophobic features at the N4 position of the thiosemicarbazone, and the reliance on the isatin moiety as key bioisosteric contributors. Additionally, a quantitative structure-activity relationship (QSAR) model that yielded a cross-validated correlation coefficient of 0.85 effectively predicts the cytotoxicty of untested thiosemicarbazones. Together, the models serve as effective approaches for predicting structures with MDR1-selective activity, and aid in directing the search for the mechanism of action of 1.

Hall, Matthew D.; Salam, Noeris K.; Hellawell, Jennifer L.; Fales, Henry M.; Kensler, Caroline B.; Ludwig, Joseph A.; Szakacs, Gergely; Hibbs, David E.; Gottesman, Michael M.

2009-01-01

130

Olfactory receptors on the maxillary palps of small ermine moth larvae: evolutionary history of benzaldehyde sensitivity  

PubMed Central

In lepidopterous larvae the maxillary palps contain a large portion of the sensory equipment of the insect. Yet, knowledge about the sensitivity of these cells is limited. In this paper a morphological, behavioral, and electrophysiological investigation of the maxillary palps of Yponomeuta cagnagellus (Lepidoptera: Yponomeutidae) is presented. In addition to thermoreceptors, CO2 receptors, and gustatory receptors, evidence is reported for the existence of two groups of receptor cells sensitive to plant volatiles. Cells that are mainly sensitive to (E)-2-hexenal and hexanal or to (Z)-3-hexen-1-ol and 1-hexanol were found. Interestingly, a high sensitivity for benzaldehyde was also found. This compound is not known to be present in Euonymus europaeus, the host plant of the monophagous Yponomeuta cagnagellus, but it is a prominent compound in Rosaceae, the presumed hosts of the ancestors of Y. cagnagellus. To elucidate the evolutionary history of this sensitivity, and its possible role in host shifts, feeding responses of three Yponomeuta species to benzaldehyde were investigated. The results confirm the hypothesis that the sensitivity to benzaldehyde evolved during the ancestral shift from Celastraceae to Rosaceae and can be considered an evolutionary relict, retained in the recently backshifted Celastraceae-specialist Y. cagnagellus.

Xu, Sen; Menken, Steph B. J.

2007-01-01

131

Inhibitors of ribonucleotide reductase. Comparative effects of amino- and hydroxy-substituted pyridine-2-carboxaldehyde thiosemicarbazones.  

PubMed

A new series of alpha-(N)-heterocyclic carboxaldehyde thiosemicarbazones (HCTs) was studied for their effects on L1210 cell growth in culture, cell cycle transit, nucleic acid biosynthesis and ribonucleotide reductase activity. 3-Aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP) and 3-amino-4-methylpyridine-2-carboxaldehyde thiosemicarbazone (3-AMP) were the most active compounds tested with respect to inhibition of cell growth and ribonucleotide reductase activity. 5-Aminopyridine-2-carboxaldehyde thiosemicarbazone (5-AP) and 4-methyl-5-aminopyridine-2-carboxaldehyde thiosemicarbazone (5-AMP) were slightly less active. 3-AP, 3-AMP, 5-AP and 5-AMP inhibited the incorporation of [3H]thymidine into DNA without affecting the rate of incorporation of [3H]uridine into RNA. The uptake and incorporation of [14C]cytidine into cellular ribonucleotides and RNA, respectively, were not decreased by 3-AP or 3-AMP; however, the incorporation of cytidine into DNA via ribonucleotide reductase was inhibited markedly. Thus, a pronounced decrease in the formation of [14C]deoxyribonucleotides from radioactive cytidine occurred in the acid-soluble fraction of 3-AP- and 3-AMP-treated L1210 cells. Consistent with an inhibition of DNA replication that occurred at relatively low concentrations of 3-AP and 3-AMP, cells gradually accumulated in the S-phase of the cell cycle; at higher concentrations of 3-AP and 3-AMP, a more rapid accumulation of cells in the G0/G1 phase of the cell cycle occurred, with the loss of the S-phase population, implying that a second less sensitive metabolic lesion was created by the HCTs. N-Acetylation of 3-AMP resulted in a compound that was 10-fold less active as an inhibitor of ribonucleotide reductase activity and 8-fold less active as an inhibitor of L1210 cell growth. N-Acetylation of either 5-AP or 5-AMP did not alter the inhibitory properties of these compounds. The results obtained provide an experimental rationale for the further development of the HCTs, particularly 3-AP and 3-AMP, as potential drugs for clinical use in the treatment of cancer. PMID:8053929

Cory, J G; Cory, A H; Rappa, G; Lorico, A; Liu, M C; Lin, T S; Sartorelli, A C

1994-07-19

132

Inner-shell spectroscopy of benzaldehyde, terephthalaldehyde, ethyl benzoate, terephthaloyl chloride, and phosgene: Models for core excitation of poly(ethylene terephthalate)  

SciTech Connect

Oscillator strengths for C 1s and O 1s excitation of terephthalaldehyde, benzaldehyde, and ethyl benzoate and C 1s, O 1s and Cl 2p excitation of terephthaloyl chloride and phosgene have been derived from electron energy loss spectra recorded under scattering conditions where electric dipole transitions dominate. Extended Hueckel molecular orbital (EHMO) calculations were used to aid interpretation of the core excitation spectra of these multifunctional organic molecules. The experimental molecular spectra and EHMO calculations were used to estimate the C 1s and O 1s core excitation spectra of poly(ethylene terephthalate) (PET). Comparisons to the C 1s and O 1s energy loss spectra of PET recorded in an electron microscope have demonstrated that gas-phase spectra and theoretical studies of molecular analogues are useful in interpreting the core excitation spectra of polymers. 48 refs., 14 figs., 13 tabs.

Hitchcock, A.P.; Urquhart, S.G. [McMaster Univ., Ontario (Canada); Rightor, E.G. [Texas Polymer Centre, Freeport, TX (United States)

1992-10-29

133

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

134

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

135

Antineoplastic and Cytotoxic Activities of Nickel(II) Complexes of Thiosemicarbazones.  

PubMed

Nickel(II) complexes of thiosemicarbazons were observed to be potent cytotoxic agents in human and rodent tissue cultured tumor cells. Each compound demonstrated a slightly different profile in the various histological types of tumors. The nickel complex of Appip demonstrated the most potent in vivo activity in the Ehrlich ascites carcinoma. This agent selectively inhibited L1210 DNA and purine syntheses, and DNA polymerase alpha, PRPP-amido transferase, IMP-dehydrogenase, dihydrofolate reductase, TMP-kinase and thymidylate synthetase activities. L1210 DNA strand scission was evident and DNA viscosity was reduced after 24 hr incubation. The nickel complexes were not L1210 DNA topoisomerase II inhibitors. PMID:18475774

Hall, I H; Miller, M C; West, D X

1997-01-01

136

SYNTHESIS, CHARACTERISATION, CATALYTIC, AND BIOCIDAL STUDIES OF RUTHENIUM(III) COMPLEXES WITH THIOSEMICARBAZONES OF ?-DIKETOESTERS  

Microsoft Academic Search

Ruthenium(III) complexes, [RuX(EPh3)2(L)] (X=Cl, Br; E=P, As; L=tridentate Schiff base dianion), have been synthesised by reacting [RuCl3(PPh3)3], [RuCl3(AsPh3)3] or [RuBr3(AsPh3)3] with thiosemicarbazones of methyl- and ethyl acetoacetates. All of the new complexes have been characterised by elemental analyses, IR, electronic, EPR and cyclic voltammetric data and an octahedral structure has been tentatively proposed. The ruthenium(III) complexes were found to be

C. Jayabalakrishnan; R. Karvembu; K. Natarajan

2002-01-01

137

Determination of thermodynamic parameters of some complexes of 2-methylindole-3-carboxaldehyde 4-phenyl-3-thiosemicarbazone  

Microsoft Academic Search

Cobalt(II), Ni(II), Cu(II) and Hg(II) form 1:2 (metal-ligand) complexes with 2-methyl-indole-3-carboxaldehyde 4-phenyl-3-thiosemicarbazone. The stability constants of these complexes in 60% (v\\/v) aqueous DMF were determined at different ionic strengths (0.10, 0.20 and 0.40 M KNO3) and of 25, 30, 35 and 40°C (±0.1°C) using a spectrophotometric method. From these constants, the thermodynamic stability constants and thermodynamic parameters ?G?, ?H? and

Tevfik Atalay; Erdal Özkan

1995-01-01

138

SYNTHESIS AND CHARACTERIZATION OF TRANSITION METAL TERNARY COMPLEXES OF GLYOXYLIC ACID THIOSEMICARBAZONE AND 4,5-DIAZAFLUOREN-9ONE  

Microsoft Academic Search

A series of transition metal ternary complexes of glyoxylic acid thiosemicarbazone and 4,5-diazafluoren-9-one were prepared and characterized by elemental analyses, conductivity and magnetic susceptibility measurements,IR, H NMR and electronic spectra. Octahedral geometry for the complexes is suggested.

Laijin Tian; Bin Zhao; Zhengyu Zhou; Qingsen Yu; Wentao Yu

2002-01-01

139

Synthesis and Characterization of Transition Metal Ternary Complexes of Glyoxylic Acid Thiosemicarbazone and 1,10-Phenanthroline  

Microsoft Academic Search

A series of transition metal ternary complexes of glyoxylic acid thiosemicarbazone (H2GATSC) and 1,10-phenanthroline (1,10-phen) have been prepared and characterized by elemental analyses, IR and electronic spectra, conductivity and magnetic susceptibility measurements. Octahedral geometry is suggested for the complexes. Their low molar conductance values are indicative of their non-electrolytic nature.

Shuxiang Liu; Junlian Tian; Enqing Gao; Siwei Bi; Yantuan Li

1996-01-01

140

Alkyl substituted 2'-benzoylpyridine thiosemicarbazone chelators with potent and selective anti-neoplastic activity: novel ligands that limit methemoglobin formation.  

PubMed

Thiosemicarbazone chelators, including the 2'-benzoylpyridine thiosemicarbazones (BpT) class, show marked potential as anticancer agents. Importantly, 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP) has been investigated in >20 phase I and II clinical trials. However, side effects associated with 3-AP administration include methemoglobinemia. Considering this problem, novel BpT analogues were designed bearing hydrophobic, electron-donating substituents at the para position of the phenyl group (RBpT). Their Fe(III/II) redox potentials were all within the range accessible to cellular oxidants and reductants, suggesting they can redox cycle. These RBpT ligands exhibited potent and selective antiproliferative activity, which was comparable or exceeded their BpT counterparts. Major findings include that methemoglobin formation mediated by the lipophilic t-BuBpT series was significantly (p < 0.05-0.001) decreased in comparison to 3-AP in intact red blood cells and were generally comparable to the control. These data indicate the t-BuBpT ligands may minimize methemoglobinemia, which is a marked advantage over 3-AP and other potent thiosemicarbazones. PMID:23276209

Stefani, Christian; Jansson, Patric J; Gutierrez, Elaine; Bernhardt, Paul V; Richardson, Des R; Kalinowski, Danuta S

2012-12-31

141

Mononuclear ruthenium(III) complexes containing chelating thiosemicarbazones: Synthesis, characterization and catalytic property  

NASA Astrophysics Data System (ADS)

Mononuclear ruthenium(III) complexes of the type [RuX(EPh 3) 2(L)] (E = P or As; X = Cl or Br; L = dibasic terdentate dehydroacetic acid thiosemicarbazones) have been synthesized from the reaction of thiosemicarbazone ligands with ruthenium(III) precursors, [RuX 3(EPh 3) 3] (where E = P, X = Cl; E = As, X = Cl or Br) and [RuBr 3(PPh 3) 2(CH 3OH)] in benzene. The compositions of the complexes have been established by elemental analysis, magnetic susceptibility measurement, FT-IR, UV-vis and EPR spectral data. These complexes are paramagnetic and show intense d-d and charge transfer transitions in dichloromethane. The complexes show rhombic EPR spectra at LNT which are typical of low-spin distorted octahedral ruthenium(III) species. All the complexes are redox active and display an irreversible metal centered redox processes. Complex [RuCl(PPh 3) 2(DHA-PTSC)] ( 5) was used as catalyst for transfer hydrogenation of ketones in the presence of isopropanol/KOH and was found to be the active species.

Raja, N.; Ramesh, R.

2010-02-01

142

Spectral characterization of iron(III) complexes of 2-benzoylpyridine N(4)-substituted thiosemicarbazones.  

PubMed

Three iron(III) complexes (1-3) of 2-benzoylpyridine N(4)-phenyl thiosemicarbazone (HL1) and one iron(III) complex (4) of 2-benzoylpyridine N(4)-cyclohexyl thiosemicarbazone (HL2) were synthesized and characterized by means of different physicochemical techniques viz., molar conductivity measurements, magnetic susceptibility studies and electronic, infrared and EPR spectral studies. The analytical data and the molar conductance measurements of the complexes reveal that two molecules of the ligand and the anion are coordinated to the metal atom in all the four complexes. The magnetic moments of the complexes suggest that they are of low spin. From the infrared spectra of the ligands and the complexes it is confirmed that the ligands coordinate to iron(III) as an anion coordinating via the azomethine nitrogen, pyridyl nitrogen, and the thiolate sulphur. The EPR spectra of the complexes in the polycrystalline state at 298 and 110 K and in DMF solution at 110 K were recorded and all the spectra show three g values indicating that these complexes have rhombic distortion. All the iron(III) complexes in DMF solution at 110 K have similar anisotropic spectra with almost the same gav values, indicating that the bonding in all the complexes is similar and is unaffected by the coordination of the anion. PMID:16386946

Joseph, Marthakutty; Sreekanth, Anandaram; Suni, V; Kurup, M R Prathapachandra

2006-01-18

143

Phosphorescence microwave double resonance and spectroscopic studies of the radiative mechanisms of benzaldehyde type 3pi* aromatic carbonyls  

Microsoft Academic Search

We have made a detailed investigation of the vibronic band dependence of the radiative decay rates from the spin sublevels of the 3pipi* aromatic carbonyls of the benzaldehyde type. The sublevel phosphorescence spectra were obtained for representative systems. It is shown that the emissions from the z and x sublevels are active at the 0-0 and the vibronic bands involving

Edward T. Harrigan; Noboru Hirota

1976-01-01

144

Unsymmetrical salen-type ligands: high yield synthesis of salen-type Schiff bases containing two different benzaldehyde moieties  

Microsoft Academic Search

Salen-type Schiff base ligands incorporating two different benzylidene moieties and a diamine backbone were synthesized in high yield (80–90%) under mild conditions via a stepwise approach. In the first step, anhydrous hydrochloric acid was used to selectively protect one amino group of the vicinal diamine backbone. The resulting ammonium salt was added to a substituted benzaldehyde providing access to a

E. Joseph Campbell; SonBinh T Nguyen

2001-01-01

145

Bis(2-hydroxy-3-isopropyl-6-methyl-benzaldehyde)ethylenediamine: a novel cation sensor.  

PubMed

Novel substituted phenol-based new symmetrical bis(2-hydroxy-3-isopropyl-6-methyl-benzaldehyde)ethylenediamine (1) has been designed and synthesized. The compound 1 fluorometrically recognized Cu(2+) ion in CH3OH/H2O (90:10, v/v) by exhibiting an increase in emission upon complexation. In addition, Cu(2+) gave rise to a change in colour of the solution of compound 1, which was clearly visible to the naked eye under UV irradiation. The association constant (K) of compound 1 with Cu(2+) ion was computed with the Benesi-Hildebrand plot and Scatchard plot at 43,000 M(-1) and 43,011 M(-1) respectively. PMID:23681946

Kuwar, Anil S; Fegade, Umesh A; Tayade, Kundan C; Patil, Umesh D; Puschmann, Horst; Gite, Vikas V; Dalal, Dipak S; Bendre, Ratnamala S

2013-05-17

146

Nonlinear optical application of a 3-methoxy-4-hydroxy-benzaldehyde single crystal  

NASA Astrophysics Data System (ADS)

The linear and nonlinear optical properties of a high-efficiency organic nonlinear optical crystal, 3-methoxy-4-hydroxy-benzaldehyde (MHBA), are investigated. The principal refractive indices at (lambda) equals 532 mn are nx equals 1.70331, ny equals 1.5624, and nz equals 1.81376. Calculations show interesting critical phase-matching properties (frequency doubling of the Nd:YAG laser at 1064 nm and diode laser at 830 nm). The nonlinear optical coefficients, d21 equals 25d36KDP +/- 10%, d22 equals 10d36KDP +/- 10%, d23 equals 33.3d36KDP +/- 10%, d24 equals 8.3d36KDP +/- 20%, were determined. MHBA has potential as a practical frequency doubler of Nd:YAG and diode lasers.

Zhang, Nan; Yuan, Dou-Rong; Shao, Zongshu; Tao, Xu-Tang; Dou, S. X.; Xu, D.; Jiang, Min-Hua

1994-09-01

147

Spectroscopic, thermal and biological studies on some trivalent ruthenium and rhodium NS chelating thiosemicarbazone complexes.  

PubMed

The synthetic, spectroscopic, and biological studies of sixteen ring-substituted 4-phenylthiosemicarbazones and 4-nitrophenyl-thiosemicarbazones of anisaldehyde, 4-chlorobenzaldehyde, 4-fluorobenzaldehyde, and vanillin with ruthenium(III) and rhodium(III) chlorides are reported here. Their structures were determined on the basis of the elemental analyses, spectroscopic data (IR, electronic, (1)H and (13)C NMR) along with magnetic susceptibility measurements, molar conductivity and thermogravimetric analyses. Electrical conductance measurement revealed a 1 : 3 electrolytic nature of the complexes. The resulting colored products are monomeric in nature. On the basis of the above studies, three ligands were suggested to be coordinated to each metal atom by thione sulphur and azomethine nitrogen to form low-spin octahedral complexes with ruthenium(III) while forming diamagnetic complexes with rhodium(III). Both ligands and their complexes have been screened for their bactericidal activities and the results indicate that they exhibit a significant activity. PMID:17505530

Sharma, Vinod K; Srivastava, Shipra; Srivastava, Ankita

2007-03-06

148

Quinoline-2-aldehyde thiosemicarbazone (QAT) as spectrophotometric reagent for palladium and nickel.  

PubMed

A procedure is described for the extractive spectrophotometric determination of nickel and palladium with quinoline-2-aldehyde thiosemicarbazone. At pH 7.5 nickel forms a 1:2 complex which is soluble in chloroform and has an absorption maximum at 460 nm. Palladium forms a 1:2 complex with maximum absorbance at 510 nm which can be extracted into MIBK from 1M HCl. Both complexes are stable and conform to Beer's law. The molar absorptivities for nickel and palladium are 1.58 x 10(4) and 2.6 x 10(3) 1.mole(-1). cm(-1) respectively. The proposed method is suitable for detection and determination of nickel and palladium in the presence of associated metal ions. The results of the analysis of synthetic mixtures and standard samples are reported. PMID:18962496

Khasnis, D V; Shinde, V M

1979-07-01

149

Phase I and pharmacokinetic study of 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3AP) using a single intravenous dose schedule  

Microsoft Academic Search

Purpose. To perform a phase I and pharmacokinetics study of 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP) a new ribonucleotide reductase inhibitor using a single intravenous (2-h) schedule every 4 weeks. 3-AP was given at a starting dose of 5 mg\\/m2 with escalation based on a modified Fibonacci scheme. Patients and methods. A total of 27 patients with advanced cancer were entered into the

Lynn Feun; Manuel Modiano; King Lee; John Mao; Angela Marini; Niramol Savaraj; Patricia Plezia; Bijan Almassian; Elizabeth Colacino; Jessica Fischer; Susan MacDonald

2002-01-01

150

A phase I trial of 3-aminopyridine-2-carboxaldehyde thiosemicarbazone in combination with gemcitabine for patients with advanced cancer  

Microsoft Academic Search

Purpose 3-Aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP), a new and potent inhibitor of ribonucleotide reductase (RR), increases the cellular uptake, DNA incorporation, and cytotoxicity of gemcitabine in tumor cell lines. A phase I trial was initiated to determine the safety profile and maximum tolerated doses of 3-AP and gemcitabine when used in combination in patients with advanced cancer. Study design 3-AP and gemcitabine

Yun Yen; Kim Margolin; James Doroshow; Mayer Fishman; Bonny Johnson; Caroline Clairmont; Dan Sullivan; Mario Sznol

2004-01-01

151

Bp44mT: an orally active iron chelator of the thiosemicarbazone class with potent anti-tumour efficacy  

PubMed Central

BACKGROUND AND PURPOSE Our previous studies demonstrated that a thiosemicarbazone iron chelator (di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone; Dp44mT) possesses potent and selective anti-cancer activity but led to cardiotoxicity at non-optimal doses. In this study, we examined the in vivo anti-tumour efficacy and tolerability of a new-generation 2-benzoylpyridine thiosemicarbazone iron chelator (2-benzoylpyridine-4,4-dimethyl-3-thiosemicarbazone; Bp44mT) administered via the oral or i.v. routes. EXPERIMENTAL APPROACH BpT chelators were tested in vitro against human lung cancer cells (DMS-53) and in vivo in DMS-53 tumour xenografts in mice. The toxicity of Bp44mT in vivo and its effects on the expression of iron-regulated molecules involved in growth and cell cycle control were investigated. KEY RESULTS Administration of Bp44mT by either route resulted in marked dose-dependent inhibition of tumour growth. When administered at 50 mg·kg?1 via oral gavage three times per week for 23 days, the net xenograft growth was inhibited by 75%, compared with vehicle-treated mice. Toxicological examination showed reversible alterations including slight reduction of RBC count, with a decrease of liver and splenic iron levels, which confirmed iron chelation in vivo. Importantly, in contrast to Dp44mT, the chelator-treated mice did not show cardiac histological abnormalities. There was also no significant weight loss in mice, suggesting oral administration of Bp44mT was well tolerated. CONCLUSIONS AND IMPLICATIONS This is the first study to show that Bp44mT can be given orally with potent anti-tumour efficacy. Oral administration of a novel and effective chemotherapeutic agent provides the benefits of convenience for chronic dosing regimens.

Yu, Y; Rahmanto, Y Suryo; Richardson, DR

2012-01-01

152

Synthesis, characterization and antiamoebic activity of new indole-3-carboxaldehyde thiosemicarbazones and their Pd(II) complexes.  

PubMed

In continuation of our research on thiosemicarbazones and their metal complexes as antiamoebic agents, a new series of indole-3-carboxaldehyde thiosemicarbazones (TSC) 1-7 were prepared by condensing indole-3-carboxaldehyde with cycloalkylaminothiocarbonyl hydrazines. Their palladium(II) complexes of the [Pd(TSC)Cl2] type, were synthesized upon coordination with [Pd(DMSO)2Cl2]. The chemical structures of all the compounds were established by elemental analyses, electronic, IR, (1)H NMR and (13)C NMR spectral data. The structure of the complexes was further established by thermogravimetric analysis and FAB MS. Spectroscopic data revealed that thiosemicarbazones act as bidentate ligands, making use of thione sulphur and azomethine nitrogen atom for coordination to the Pd(II) ion. Among all the compounds evaluated for antiamoebic activity using HM1:IMSS strain of Entamoeba histolytica, all palladium complexes were found to be more active than their respective ligands. Moreover, ligand 5 and complexes 1a-3a, 5a and 7a showed antiamoebic activity, at lower IC(50) doses when compared to the reference drug metronidazole with IC(50)=1.81 microM. PMID:17442460

Husain, Kakul; Abid, Mohammad; Azam, Amir

2007-03-02

153

DECREASE IN OVALBUMIN-INDUCED PULMONARY ALLERGIC RESPONSE BY BENZALDEHYDE BUT NOT ACETALDEHYDE EXPOSURE IN A GUINEA PIG MODEL  

Microsoft Academic Search

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 µ g OA and 100 mg Al(OH) 3 . They were then exposed to either acetaldehyde (200 ppb) or benzaldehyde (500 ppb) for

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

2002-01-01

154

Hydrogen Transfer Reduction of 4- tert-Butylcyclohexanone and Aldol Condensation of Benzaldehyde with Acetophenone on Basic Solids  

Microsoft Academic Search

The liquid-phase reduction of 4-tert-butylcyclohexanone into 4-tert-butylcyclohexanol by reaction with isopropanol at 355 K has been studied on solid bases: mixed oxides obtained by calcination of hydrotalcites, NaBEA zeolites, KF\\/alumina, and La2O3 characterized by calorimetric FTIR adsorption of CO2 and FTIR pyridine adsorption. The aldol condensation of benzaldehyde and acetophenone at 423 K was investigated in parallel to clarify the

J. Lopez; J. Sanchez Valente; J.-M. Clacens; F. Figueras

2002-01-01

155

Preparation and characterization of new and improved soluble-starches, -amylose, and amylopectin by reaction with benzaldehyde\\/zinc chloride  

Microsoft Academic Search

Seven different starches from potato, rice, maize, waxymaize, amylomaize-VII, shoti, and tapioca, and potato amylose and potato amylopectin have been reacted with benzaldehyde, catalyzed by ZnCl2, to give new water-soluble starches and water soluble-amylose and soluble-amylopectin. In contrast to the native starches, aqueous solutions of the modified starches could not be precipitated with 2-, 3-, or 4-volumes of ethanol. ?-Amylase

David A. Johnston; Rupendra Mukerjea; John F. Robyt

156

Synthesis, crystal growth and FTIR, NMR, SHG studies of 4-methoxy benzaldehyde- N-methyl-4-stilbazolium tosylate (MBST)  

Microsoft Academic Search

A novel organic nonlinear optical material 4-methoxy benzaldehyde-N-methyl-4-stilbazolium tosylate has been synthesized and good optical quality crystals were grown by slow cooling solution growth technique. Powder X-ray diffraction studies have been carried out and the lattice parameters were calculated. FTIR spectra were recorded to identify the various functional groups present in the crystal. NMR spectrum studies have also been done.

C. K. Lakshmana Perumal; A. Arulchakkaravarthi; N. P. Rajesh; P. Santhana Raghavan; Y. C. Huang; M. Ichimura; P. Ramasamy

2002-01-01

157

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

2013-05-28

158

New copper(II) complexes of 2-hydroxyacetophenone N(4)-substituted thiosemicarbazones and polypyridyl co-ligands: structural, electrochemical and antimicrobial studies  

Microsoft Academic Search

Seven new copper(II) complexes of 2-hydroxyacetophenone N(4)-substituted thiosemicarbazones (H2L) and bidentate polypyridyl compounds 2,2?-bipyridine and 1,10-phenanthroline (B) were prepared and characterized. The thiosemicarbazones bind to the metal as dianionic ONS donors (L2?) and yield compounds of the stochiometry [MLB]. The structure of the compound [Cu(L4)(2,2?-bipy)] (6) was investigated by single-crystal X-ray diffraction method. Spin Hamiltonian and bonding parameters of the

Rohith P. John; A. Sreekanth; V. Rajakannan; T. A. Ajith; M. R. Prathapachandra Kurup

2004-01-01

159

Reaction of dimethylthallium(III) acetate and isatin-3-thiosemicarbazone. Crystal and molecular structure of dimethyl(dimethylsulfoxide)(isatin-3-thiosemicarbazonato)thallium(III)  

Microsoft Academic Search

The reaction of dimethylthallium(III) acetate and isatin-3-thiosemicarbazone (HisaTSC) afforded [TlMe2(isaTSC)], which recrystallised from DMSO as [TlMe2(isaTSC)(DMSO)]. In this crystal the Tl atom is bound to the S, N(3) and O atoms of an N(2)-deprotonated thiosemicarbazone ligand, to the O of a DMSO molecule, and to the two methyl C atoms. An additional Tl?OisaTSC interaction with a neighbouring molecule gives rise

J. S Casas; E. E Castellano; M. S Garc??a Tasende; A Sánchez; J Sordo

2000-01-01

160

An Aldehyde Oxidase in Developing Seeds of Arabidopsis Converts Benzaldehyde to Benzoic Acid1[OA  

PubMed Central

Arabidopsis (Arabidopsis thaliana) siliques synthesize high levels of benzoic acid (BA), which is incorporated into several glucosinolate compounds. The origin of BA in the siliques has not yet been determined. Here, we show that siliques have higher levels of benzaldehyde (BD)-oxidizing activity relative to leaves. The BD-oxidizing activity was purified from siliques in several chromatographic steps, and a 145-kD protein was identified as the enzyme most likely to possess this activity. The protein was trypsinized, and the sequence of the resulting peptides was determined by mass spectrometry, identifying it as the product of gene At1g04580, also designated as AAO4 (for ARABIDOPSIS ALDEHYDE OXIDASE4). AAO4 had previously been shown to be highly and specifically expressed in developing seeds, and its protein was shown to belong to a family of aldehyde oxidases. Here, we show that the AAO4 protein is an aldehyde oxidase that can use several substrates but that, among the substrates tested, has the lowest Km value (23 ?m) with BD. AAO4 is able to oxidize BD without NAD+, but its activity increases by 50% when this cofactor is added. The pH optimum of AAO4 is 7.0. Plants homozygous for a null allele in AAO4 showed a reduction of 30% to 45% in the total levels of BA in seeds as well as 7% to 9% and 32% to 38% decreases in the levels of 3-benzoyloxypropylglucosinolate and 4-benzoyloxybutylglucosinolate, respectively. Expressing AAO4 in Escherichia coli resulted in a 3-fold increase of BD-oxidizing activity in crude bacterial extracts over endogenous levels. These findings indicate that in Arabidopsis seeds, oxidation of BD contributes in part to the synthesis of BA.

Ibdah, Mwafaq; Chen, Ying-Tung; Wilkerson, Curtis G.; Pichersky, Eran

2009-01-01

161

Molecular dynamics of 6-methyl-2-phenyl-2,3-dihydro-4H-chromen-4-one and 6-methyl-2-(4-nitrophenyl)-2,3-dihydro-4H-chromen-4-one (flavanone) derivatives in a solution studied by NMR spectroscopy.  

PubMed

Molecular dynamics of benzoxazepin, oxime, pyrazole, and thiosemicarbazone derivatives of some flavanones have been investigated in a solution using NMR. The results confirm the formation of different O-H···O, O-H···N, N···H-N type intramolecular hydrogen bonds in the pyrazole and oxime molecules. The rotational barrier energy and energy of intramolecular hydrogen bonds have been determined. PMID:23420615

Mamedov, Ibrahim Garib; Bayramov, Musa Rza; Mamedova, Yegana Vagif; Maharramov, Abel Mammadali

2013-02-19

162

Identification of Semicarbazones, Thiosemicarbazones and Triazine Nitriles as Inhibitors of Leishmania mexicana Cysteine Protease CPB  

PubMed Central

Cysteine proteases of the papain superfamily are present in nearly all eukaryotes. They play pivotal roles in the biology of parasites and inhibition of cysteine proteases is emerging as an important strategy to combat parasitic diseases such as sleeping sickness, Chagas’ disease and leishmaniasis. Homology modeling of the mature Leishmania mexicana cysteine protease CPB2.8 suggested that it differs significantly from bovine cathepsin B and thus could be a good drug target. High throughput screening of a compound library against this enzyme and bovine cathepsin B in a counter assay identified four novel inhibitors, containing the warhead-types semicarbazone, thiosemicarbazone and triazine nitrile, that can be used as leads for antiparasite drug design. Covalent docking experiments confirmed the SARs of these lead compounds in an effort to understand the structural elements required for specific inhibition of CPB2.8. This study has provided starting points for the design of selective and highly potent inhibitors of L. mexicana cysteine protease CPB that may also have useful efficacy against other important cysteine proteases.

Schroder, Jorg; Noack, Sandra; Marhofer, Richard J.; Mottram, Jeremy C.; Coombs, Graham H.; Selzer, Paul M.

2013-01-01

163

Species Dependence of [64Cu]Cu-Bis(thiosemicarbazone) Radiopharmaceutical Binding to Serum Albumins  

PubMed Central

Introduction Interactions of three copper(II) bis(thiosemicarbazone) PET radiopharmaceuticals with human serum albumin, and the serum albumins of four additional mammalian species, were evaluated. Methods 64Cu-labeled diacetyl bis(N4-methylthiosemicarbazonato)copper(II) (Cu-ATSM), pyruvaldehyde bis(N4-methylthiosemicarbazonato)copper(II) (Cu-PTSM), and ethylglyoxal bis(thiosemicarbazonato)copper(II) (Cu-ETS) were synthesized and their binding to human, canine, rat, baboon, and porcine serum albumins quantified by ultrafiltration. Protein binding was also measured for each tracer in human, porcine, rat, and mouse serum. Results The interaction of these neutral, lipophilic copper chelates with serum albumin is highly compound- and species-dependent. Cu-PTSM and Cu-ATSM exhibit particularly high affinity for human serum albumin (HSA), while the albumin binding of Cu-ETS is relatively insensitive to species. At HSA concentrations of 40 mg/mL, “% Free” (non-albumin-bound) levels of radiopharmaceutical were 4.0 ± 0.1%; 5.3 ± 0.2%; and 38.6 ± 0.8% for Cu-PTSM; Cu-ATSM; and Cu-ETS, respectively. Conclusions Species-dependent variations in radiopharmaceutical binding to serum albumin may need to be considered when using animal models to predict the distribution and kinetics of these compounds in humans.

Basken, Nathan E.; Mathias, Carla J.; Lipka, Alexander E.; Green, Mark A.

2008-01-01

164

Identification of Semicarbazones, Thiosemicarbazones and Triazine Nitriles as Inhibitors of Leishmania mexicana Cysteine Protease CPB.  

PubMed

Cysteine proteases of the papain superfamily are present in nearly all eukaryotes. They play pivotal roles in the biology of parasites and inhibition of cysteine proteases is emerging as an important strategy to combat parasitic diseases such as sleeping sickness, Chagas' disease and leishmaniasis. Homology modeling of the mature Leishmania mexicana cysteine protease CPB2.8 suggested that it differs significantly from bovine cathepsin B and thus could be a good drug target. High throughput screening of a compound library against this enzyme and bovine cathepsin B in a counter assay identified four novel inhibitors, containing the warhead-types semicarbazone, thiosemicarbazone and triazine nitrile, that can be used as leads for antiparasite drug design. Covalent docking experiments confirmed the SARs of these lead compounds in an effort to understand the structural elements required for specific inhibition of CPB2.8. This study has provided starting points for the design of selective and highly potent inhibitors of L. mexicana cysteine protease CPB that may also have useful efficacy against other important cysteine proteases. PMID:24146999

Schröder, Jörg; Noack, Sandra; Marhöfer, Richard J; Mottram, Jeremy C; Coombs, Graham H; Selzer, Paul M

2013-10-16

165

Development of a parenteral formulation of an investigational anticancer drug, 3-aminopyridine-2-carboxaldehyde thiosemicarbazone.  

PubMed

The objective of this study was to develop an injectable formulation of 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP) suitable for intravenous infusion. The solubility of 3-AP in different solvents and pH conditions was determined. The developed formulation underwent stability assessment and compatibility testing with large volume parenteral (LVP) solutions. The aqueous solubility of 3-AP was found to be 0.1 mg/ml and could only be increased marginally by altering the pH or adding surfactants. To achieve the desired concentration (> 4 mg/ml), 3-AP was formulated at 5-10 mg/ml in a nonaqueous system consisting of 70% polyethylene glycol 300 and 30% ethanol. However, 3-AP readily precipitated from this formulation when diluted with LVP solutions. Dilution-induced drug precipitation was eliminated by acidifying the solution with citric acid. Ascorbic acid, 0.1%, was found to minimize oxidative degradation of 3-AP. Accelerated stability data indicated that the formulation is compatible with the packaging components and is chemically stable at 2-8 degrees C, and retained > 90% of 3-AP at 40 degrees C for 3 months. Simulated infusion studies showed that the citric acid formulation was compatible with LVP solutions. However, because of the potential of extraction of plasticizers from polyvinyl chloride (PVC) plastic containers, it is recommended that the formulation be diluted in glass containers prior to administration. PMID:10027215

Krishna, G; Mao, J; Almassian, B; Lang, W

1999-01-01

166

Syntheses, structural and spectral studies of six-coordinate, [Ph2SnCl(acpm)], and seven-coordinate, [nBu2Sn(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 Ph2SnCl2 leads to the formation of the six-coordinate complex [Ph2SnCl(acpm)] (1), whereas the reaction of the S,N,N,N,S-pentadentate ligand 2,6-diacetylpyridine bis(N4-morpholyl thiosemicarbazone), H2dapm, with nBu2SnCl2 leads to the formation of the seven-coordinate complex [nBu2Sn(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 acpm1- 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 (P21/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

167

Synthesis and antimicrobial evaluation of some new thiazole, thiazolidinone and thiazoline derivatives starting from 1-chloro-3,4-dihydronaphthalene-2-carboxaldehyde  

Microsoft Academic Search

The thiosemicarbazones (3 and 6) and N-arylidene cyanoacetohydrazide (12) were prepared and used as key intermediates for the synthesis of 4-thiazolidinones (4, 5, 7–9), thiazoles (10a,b and 11a–d) and thiazoline (13) derivatives. Treatment of 13 with a mixture of triethylorthoformate and acetic anhydride afforded thiazolo[5,4-d]pyrimidinone derivative (14). The newly synthesized compounds were characterized by IR, 1H NMR and mass spectral

Samir Bondock; Wesam Khalifa; Ahmed A. Fadda

2007-01-01

168

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

2012-11-06

169

Investigation of Thiosemicarbazones as Chelating Agents. Synthesis and Spectroscopic Characterization of Some New Ruthenium(III) Complexes  

Microsoft Academic Search

New octahedral complexes of Ru(III) with salicylaldehyde, 5?chlorosalicylaldehyde, 5?methoxysalicylaldeyhyde, 2?hydroxynaphth?aldehyde and dehydroacetic acid thiosemicarbazones have been synthesized and characterized by elemental analyses, IR, UV?Vis. spectra, magnetic moments, conductivity, ESR spectra and thermal analysis. The molar conductance measurements indicate that, the complexes are non?electrolytes except for complex (LH)2Ru]Cl·2H2O (10). The ESR spectra of the complexes (LH)Ru(Cl)2(H2O)·2H2O (9) and (LH)2Ru]Cl·2H2O (10), (LH2 = dehydroacetic

Mohamed Ibrahim Ayad

2003-01-01

170

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

NASA Astrophysics Data System (ADS)

Novel N3-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.

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

2013-10-01

171

Effects of pulse feeding of beet molasses on recombinant benzaldehyde lyase production by Escherichia coli BL21(DE3)  

Microsoft Academic Search

The effect of fed-batch operation (FBO) strategy was investigated using pretreated-beet molasses, containing galactose that\\u000a induces the lac promoter, on benzaldehyde lyase (BAL) production by recombinant Escherichia coli BL21(DE3)pLySs. After batch cultivation with 30 g l?1 pretreated-beet molasses consisting of 7.5 g l?1 glucose and 7.5 g l?1 fructose, three FBO strategies were applied at dissolved oxygen (=40%) cascade to air-flow rate. In

P?nar Çal?k; Hande Levent

2009-01-01

172

Fluorescence properties and cellular distribution of the investigational anticancer drug triapine (3-aminopyridine-2-carboxaldehyde thiosemicarbazone) and its zinc(II) complex.  

PubMed

Triapine (3-aminopyridine-2-carboxaldehyde thiosemicarbazone), which entered several phase I and II clinical trials as an antitumor chemotherapeutic agent, was found to possess intrinsic fluorescence properties (lambda(ex) = 360 nm), which enabled us to monitor the uptake and intracellular distribution in living human cancer cells by fluorescence microscopy. PMID:20066211

Kowol, Christian R; Trondl, Robert; Arion, Vladimir B; Jakupec, Michael A; Lichtscheidl, Irene; Keppler, Bernhard K

2009-10-22

173

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

174

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

2013-09-30

175

Ruthenium hydride-catalyzed regioselective addition of benzaldehyde to dienes leading to ?,?-unsaturated ketones: a DFT study.  

PubMed

Density functional theory (DFT) was used to investigate the ruthenium hydride-catalyzed regioselective addition reactions of benzaldehyde to isoprene leading to the branched ?,?-unsaturated ketone. All intermediates and the transition states were optimized completely at the B3LYP/6-31 G(d,p) level (LANL2DZ(f) for Ru, LANL2DZ(d) for P and Cl). Calculated results indicated that three catalysts RuHCl(CO)(PMe(3))(3) (1), RuH(2)(CO)(PMe(3))(3) (2), and RuHCl(PMe(3))(3) (3) exhibited different catalysis, and the first was the most excellent. The most favorable reaction pathway included the coordination of 1 to the less substituted olefin of isoprene, a hydrogen transfer reaction from ruthenium to the carbon atom C1, the complexation of benzaldehyde to ruthenium, the carbonyl addition, and the hydride elimination reaction. The carbonyl addition was the rate-determining step. The dominant product was the branched ?,?-unsaturated ketone. Furthermore, the presence of one toluene molecule lowered the activation free energy of the transition state of the carbonyl addition by hydrogen bonds between the protons of toluene and the chlorine, carbonyl oxygen of the ruthenium complex. On the whole, the solvent effect decreased the free energies of the species. PMID:22722699

Meng, Qingxi; Wang, Fen; Li, Ming

2012-06-22

176

Fe(iii)-photocatalytic partial oxidation of benzyl alcohol to benzaldehyde under UV-solar simulated radiation.  

PubMed

A great deal of interest is recorded among researchers in the identification of new catalytic systems that make possible the selective oxidation of organic species in the presence of non-toxic solvents, primarily water, through the use of inexpensive catalysts. The possibility to selectively oxidize benzyl alcohol to benzaldehyde is studied in the present work by using ferric ions as homogeneous catalysts and oxygen as an oxidant under UV-solar simulated radiation. Due to the possibility that Fe(iii) aquo-complex photolysis could generate undesired reactive OH radicals with the consequent occurrence of side reactions, most of the runs are carried out at pH = 0.5 at which these events have a reduced incidence. The results indicate that benzyl alcohol can be partially converted into benzaldehyde with yield and selectivity values higher than 40% and 80% respectively for the conditions adopted, with a minor occurrence of benzoic acid formation. Reaction schemes to account for the experimental observations are provided. PMID:24057651

Spasiano, Danilo; Marotta, Raffaele; Di Somma, Ilaria; Andreozzi, Roberto; Caprio, Vincenzo

2013-10-16

177

Interaction of Triapine and related thiosemicarbazones with iron(III)/(II) and gallium(III): a comparative solution equilibrium study.  

PubMed

Stoichiometry and stability of Ga(III), Fe(III), Fe(II) complexes of Triapine and five related ?-N heterocyclic thiosemicarbazones with potential antitumor activity have been determined by pH-potentiometry, UV-vis spectrophotometry, (1)H NMR spectroscopy, and spectrofluorimetry in aqueous solution (with 30% DMSO), together with the characterization of the proton dissociation processes. Additionally, the redox properties of the iron complexes were studied by cyclic voltammetry at various pH values. Formation of high stability bis-ligand complexes was found in all cases, which are predominant at physiological pH with Fe(III)/Fe(II), whilst only at the acidic pH range with Ga(III). The results show that among the thiosemicarbazones with various substituents the N-terminal dimethylation does not exert a measurable effect on the redox potential, but has the highest impact on the stability of the complexes as well as the cytotoxicity, especially in the absence of a pyridine-NH(2) group in the molecule. In addition the fluorescence properties of the ligands in aqueous solution and their changes caused by Ga(III) were studied. PMID:21523301

Enyedy, Éva A; Primik, Michael F; Kowol, Christian R; Arion, Vladimir B; Kiss, Tamás; Keppler, Bernhard K

2011-04-27

178

Interaction of Triapine and related thiosemicarbazones with iron(III)/(II) and gallium(III): a comparative solution equilibrium study+  

PubMed Central

Stoichiometry and stability of GaIII, FeIII, FeII complexes of Triapine and five related ?-N heterocyclic thiosemicarbazones with potential antitumor activity have been determined by pH-potentiometry, UV-vis spectrophotometry, 1H NMR spectroscopy, and spectrofluorimetry in aqueous solution (with 30% DMSO), together with the characterization of the proton dissociation processes. Additionally, the redox properties of the iron complexes were studied by cyclic voltammetry at various pH values. Formation of high stability bis-ligand complexes was found in all cases, which are predominant at physiological pH with FeIII/FeII, whilst only at the acidic pH range with GaIII. The results show that among the thiosemicarbazones with various substituents the N-terminal dimethylation does not exert a measurable effect on the redox potential, but has the highest impact on the stability of the complexes as well as the cytotoxicity, especially in the absence of a pyridine-NH2 group in the molecule. In addition the fluorescence properties of the ligands in aqueous solution and their changes caused by GaIII were studied.

Enyedy, Eva A.; Primik, Michael F.; Kowol, Christian R.; Arion, Vladimir B.; Kiss, Tamas; Keppler, Bernhard K.

2012-01-01

179

Studies on the mechanism of hypoxic selectivity in copper bis(thiosemicarbazone) radiopharmaceuticals.  

PubMed

Copper diacetyl-bis(N4-methylthiosemicarbazone), Cu(II)ATSM, is a promising agent for imaging hypoxic tissue. Here we present results that provide insight into the chemical and electronic properties underlying previously observed structure-activity relationships. Density functional theory (DFT) calculations on the electronic structures and molecular orbitals of a series of 13 Cu(II)bis(thiosemicarbazone) analogues with different alkylation patterns and with fixed geometries based on the known structure of Cu(II)PTSM showed that the LUMO and the next lowest orbital were very close in energy, and their energy order was strikingly dependent on the ligand alkylation pattern in a way that correlated with hypoxia-selectivity and redox potentials. The LUMOs of Cu(II)ATSM and other hypoxia-selective analogues were predominantly metal-based (leading to a singlet reduced species) while the LUMOs of Cu(II)PTSM and other nonselective analogues were predominantly ligand-based (leading to a triplet reduced species). Upon relaxation of the geometric constraint and full optimization in both Cu(II)ATSM and Cu(II)GTS, the metal-based orbital became the LUMO, and the singlet was the thermodynamically preferred form of the reduced species. Chemical and electrochemical investigation showed that all Cu(II) complexes were reducible, but Cu(I)PTSM and other nonselective analogues dissociated immediately upon reduction with release of ligand (detected by UV-vis) while Cu(I)ATSM and other hypoxia-selective analogues did not. Instead they were rapidly re-oxidized to the Cu(II) complex by molecular oxygen. The reversible electrochemical reduction of nonselective complexes Cu(II)PTSM and Cu(II)GTS became irreversible in the presence of weak acid, whereas that of Cu(II)ATSM was unaffected. In light of these results we present a model to explain the structure-activity relationships on the basis of electronic structure and molecular vibrations. PMID:11906283

Maurer, Richard I; Blower, Philip J; Dilworth, Jonathan R; Reynolds, Christopher A; Zheng, Yifan; Mullen, Gregory E D

2002-03-28

180

Neuroprotective activity of 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (PAN-811), a cancer therapeutic agent.  

PubMed

3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP) is a highly-hydrophobic small molecule that was originally developed for cancer therapy (Triapine, Vion Pharmaceuticals) due to its ability to inhibit ribonucleotide reductase, a key enzyme required for DNA synthesis. 3-AP has a high affinity for divalent cations, chelating the Fe(2+) at the R2 subunit of the enzyme and inhibiting formation of a tyrosyl radical essential for ribonucleotide reduction. We have demonstrated that 3-AP is also a potent neuroprotectant (as such, it is referred to as "PAN-811"). In vitro it completely blocks ischemic neurotoxicity at a concentration of 0.5 microM (EC(50) approximate, equals 0.35 microM) and hypoxic toxicity at 1.2 microM (EC(50) approximate, equals 0.75 microM). Full protection of primary cortical and striatal neurons can be achieved with 3-AP when it is added to the medium at up to six hours after an ischemic insult. 3-AP also suppresses cell death induced by neurotoxic agents, including staurosporine, veratridine and glutamate, indicating activity against a central target(s) in the neurodegenerative process. 3-AP acts via neutralization of two important intracellular effectors of excitatory neurotoxicity; calcium and free radicals. Its reported ability to elevate anti-apoptotic proteins is likely to be a consequence of the suppression of excessive intracellular free calcium. In a rat model of transient ischemia, a single bolus delivery of 3-AP 1 h after the initiation of ischemic attack reduced infarct volume by 59% when administered i.c.v. (50 mug per rat) and by 35% when administered i.v. (1 mg/kg). In Phase I clinical trials in cancer therapy 3-AP had no cardiovascular, CNS or other major adverse effects. Thus, 3-AP has a high potential for development as a novel, potent neuroprotectant for the treatment of neurodegenerative diseases. PMID:16834759

Jiang, Zhi-Gang; Lebowitz, Michael S; Ghanbari, Hossein A

2006-01-01

181

Synthesis and antifungal activity of N-benzyl derivatives of amphotericin B  

Microsoft Academic Search

N-Benzyl derivatives of the polyene macrolide antibiotic amphotericin B were formed by reacting it with benzaldehydes and\\u000a cyanoborohydride under reductive amination conditions. The physicochemical and biological properties of the resulting amphotericin\\u000a B derivatives were studied. The N-benzyl derivatives of amphotericin B had high antifungal activity against a broad range of test cultures. Biological studies\\u000a found that the acute toxicity of

V. V. Belakhov; Yu. D. Shenin

2007-01-01

182

Membrane transport and intracellular sequestration of novel thiosemicarbazone chelators for the treatment of cancer.  

PubMed

Iron is a critical nutrient for DNA synthesis and cellular proliferation. Targeting iron in cancer cells using specific chelators is a potential new strategy for the development of novel anticancer agents. One such chelator, 2-benzoylpyridine 4-ethyl-3-thiosemicarbazone (Bp4eT), possesses potent and selective anticancer activity (J Med Chem 50:3716-3729, 2007). To elucidate the mechanisms of its potent antitumor activity, Bp4eT was labeled with (14)C. Its efficacy was then compared with the (14)C-labeled iron chelator pyridoxal isonicotinoyl hydrazone (PIH), which exhibits low anticancer activity. The ability of these ligands to permeate the cell membrane and their cellular retention was examined under various conditions using SK-N-MC neuroepithelioma cells. The rate of [(14)C]PIH uptake into cells was significantly (p < 0.001) lower than that of [(14)C]Bp4eT at 37°C, indicating that the increased hydrophilicity of [(14)C]PIH reduced membrane permeability. In contrast, the efflux of [(14)C]PIH was significantly (p < 0.05) higher than that of [(14)C]Bp4eT, leading to increased cellular retention of [(14)C]Bp4eT. In addition, the uptake and release of the (14)C-labeled chelators was not reduced by metabolic inhibitors, indicating that these processes were energy-independent. No significant differences were evident in the uptake of [(14)C]Bp4eT at 37 or 4°C, demonstrating a temperature-independent mechanism. Furthermore, adjusting the pH of the culture medium to model the tumor microenvironment did not affect [(14)C]Bp4eT membrane transport. It can be concluded that [(14)C]Bp4eT more effectively permeated the cell membrane and evaded rapid efflux in contrast to [(14)C]PIH. This property, in part, accounts for the more potent anticancer activity of Bp4eT relative to PIH. PMID:20605952

Merlot, Angelica M; Pantarat, Namfon; Lovejoy, David B; Kalinowski, Danuta S; Richardson, Des R

2010-07-06

183

Single-crystal growth of 4-hydroxy-3-methoxy benzaldehyde by the Bridgman technique and its characterization  

NASA Astrophysics Data System (ADS)

Single-crystal growth of 4-hydroxy-3-methoxy benzaldehyde (vanillin), an excellent molecular nonlinear optical (NLO) material, from the melt using the Bridgman technique is reported for the first time. Differential thermal analysis experiments indicated that the substance melts congruently at 81 °C. A precise temperature profile plot of the resistive furnace used was measured using a simple PC-based time-temperature data logging system. Powder X-ray diffraction analysis of the grown crystal revealed the crystal belongs to the monoclinic system. Fourier transform infrared spectra were used to assign various modes and identify the functional groups. The crystal exhibited a wide window of transmission unlike other organic NLO crystals. The optical second harmonic generation conversion efficiency of vanillin was determined using the Kurtz powder technique.

Kannan, V.; Jayaprakasan, M.; Bairava Ganesh, R.; Ramasamy, P.

2006-08-01

184

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

185

Four and Eight Carbon Homologation of Benzaldehyde by (1Z,3Z)-Butyltelluro-1,3Butadiene. Synthesis of Navenone B: Alarm Pheromone of the Mollusk Navanax Inermis  

Microsoft Academic Search

Four- and eight-carbon homologation of benzaldehydes is described. The hydrotelluration of (Z)-1-methoxy-but-1-en-3-ynes 1 afforded (1Z,3Z)-1-butyltelluro-4-methoxy-1,3-butadiene 2, this compound 2 underwent a Te\\/Li exchange reaction, and the butadienyllithium 3 obtained reacted with benzaldehyde to form the corresponding allylic alcohol 4 with total retention of configuration. The allylic alcohol 4a formed underwent acidic hydrolysis, resulting in 5-phenyl-(2E,4E)-dienal 5 (four-carbon homologation of benzaldehyde).

Miguel J. Dabdoub; Vânia B. Dabdoub; Adriano C. M. Baroni; Sandro L. Barbosa

2011-01-01

186

Four and Eight-Carbon Homologation of Benzaldehyde by (1Z,3Z)-Butyltelluro-1,3Butadiene: Synthesis of Navenone B: Alarm Pheromone of the Mollusk Navanax inermis  

Microsoft Academic Search

Four- and eight-carbon homologation of benzaldehydes is described. The hydrotelluration of (Z)-1-methoxy-but-1-en-3-ynes 1 afforded (1Z,3Z)-1-butyltelluro-4-methoxy-1,3-butadiene 2, this compound 2 underwent a Te\\/Li exchange reaction, and the butadienyllithium 3 obtained reacted with benzaldehyde to form the corresponding allylic alcohol 4 with total retention of configuration. The allylic alcohol 4a formed underwent acidic hydrolysis, resulting in 5-phenyl-(2E,4E)-dienal 5 (four-carbon homologation of benzaldehyde).

Miguel J. Dabdoub; Vânia B. Dabdoub; Adriano C. M. Baroni; Sandro L. Barbosa

2012-01-01

187

Ribonucleotide reductase inhibition by metal complexes of Triapine (3-aminopyridine-2-carboxaldehyde thiosemicarbazone): a combined experimental and theoretical study.  

PubMed

Triapine (3-aminopyridine-2-carboxaldehyde thiosemicarbazone, 3-AP) is currently the most promising chemotherapeutic compound among the class of ?-N-heterocyclic thiosemicarbazones. Here we report further insights into the mechanism(s) of anticancer drug activity and inhibition of mouse ribonucleotide reductase (RNR) by Triapine. In addition to the metal-free ligand, its iron(III), gallium(III), zinc(II) and copper(II) complexes were studied, aiming to correlate their cytotoxic activities with their effects on the diferric/tyrosyl radical center of the RNR enzyme in vitro. In this study we propose for the first time a potential specific binding pocket for Triapine on the surface of the mouse R2 RNR protein. In our mechanistic model, interaction with Triapine results in the labilization of the diferric center in the R2 protein. Subsequently the Triapine molecules act as iron chelators. In the absence of external reductants, and in presence of the mouse R2 RNR protein, catalytic amounts of the iron(III)-Triapine are reduced to the iron(II)-Triapine complex. In the presence of an external reductant (dithiothreitol), stoichiometric amounts of the potently reactive iron(II)-Triapine complex are formed. Formation of the iron(II)-Triapine complex, as the essential part of the reaction outcome, promotes further reactions with molecular oxygen, which give rise to reactive oxygen species (ROS) and thereby damage the RNR enzyme. Triapine affects the diferric center of the mouse R2 protein and, unlike hydroxyurea, is not a potent reductant, not likely to act directly on the tyrosyl radical. PMID:21955844

Popovi?-Bijeli?, Ana; Kowol, Christian R; Lind, Maria E S; Luo, Jinghui; Himo, Fahmi; Enyedy, Eva A; Arion, Vladimir B; Gräslund, Astrid

2011-07-31

188

Ribonucleotide reductase inhibition by metal complexes of Triapine (3-aminopyridine-2-carboxaldehyde thiosemicarbazone): A combined experimental and theoretical study  

PubMed Central

Triapine (3-aminopyridine-2-carboxaldehyde thiosemicarbazone, 3-AP) is currently the most promising chemotherapeutic compound among the class of ?-N-heterocyclic thiosemicarbazones. Here we report further insights into the mechanism(s) of anticancer drug activity and inhibition of mouse ribonucleotide reductase (RNR) by Triapine. In addition to the metal-free ligand, its iron(III), gallium(III), zinc(II) and copper (II) complexes were studied, aiming to correlate their cytotoxic activities with their effects on the diferric/tyrosyl radical center of the RNR enzyme in vitro. In this study we propose for the first time a potential specific binding pocket for Triapine on the surface of the mouse R2 RNR protein. In our mechanistic model, interaction with Triapine results in the labilization of the diferric center in the R2 protein. Subsequently the Triapine molecules act as iron chelators. In the absence of external reductants, and in presence of the mouse R2 RNR protein, catalytic amounts of the iron(III)–Triapine are reduced to the iron(II)–Triapine complex. In the presence of an external reductant (dithiothreitol), stoichiometric amounts of the potently reactive iron (II)–Triapine complex are formed. Formation of the iron(II)–Triapine complex, as the essential part of the reaction outcome, promotes further reactions with molecular oxygen, which give rise to reactive oxygen species (ROS) and thereby damage the RNR enzyme. Triapine affects the diferric center of the mouse R2 protein and, unlike hydroxyurea, is not a potent reductant, not likely to act directly on the tyrosyl radical.

Popovic-Bijelic, Ana; Kowol, Christian R.; Lind, Maria E.S.; Luo, Jinghui; Himo, Fahmi; Enyedy, Eva A.; Arion, Vladimir B.; Graslund, Astrid

2012-01-01

189

Novel bis(thiosemicarbazones) of the 3,5-diacetyl-1,2,4-triazol series and their platinum(II) complexes: chemistry, antiproliferative activity and preliminary nephrotoxicity studies.  

PubMed

The preparation and characterization of three novel (4)N-monosubstituted bis(thiosemicarbazone) ligands of 3,5-diacetyl-1,2,4-triazol series and their dinuclear platinum complexes are described. The crystal and molecular structure of the [Pt(?-H(3)L(3))](2) complex derived of 3,5-diacetyl-1,2,4-triazol bis((4)N-p-tolylthiosemicarbazone), H(5)L(3), has been resolved by single crystal X-ray diffraction. The ligands coordinate, in an asymmetric dideprotonate form, to the platinum ions in a tridentate fashion (NNS) and S-bridging bonding modes. Thus the molecular units of the platinum complexes are stacked as dimers. The new compounds synthesized have been evaluated for antiproliferative activity in vitro against NCI-H460, A2780 and A2780cisR human cancer cell lines. The cytotoxicity data suggest that these compounds may be endowed with important antitumour properties since are capable of not only circumventing cisplatin resistance in A2780cisR cells but also exhibit high antiproliferative activity in human non-small cell lung cancer NCI-H460 cells. The interactions of these compounds with calf thymus DNA was investigated by UV-vis absorption and a nephrotoxic study, in LLC-PK1 cells, has also been carried out. PMID:21519595

Matesanz, Ana I; Hernández, Carolina; Rodríguez, Ana; Souza, Pilar

2011-04-26

190

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

2009-12-03

191

Analytical properties of 1-phenyl-1,2-propanedione-2-oxime thiosemicarbazone: simultaneous spectrophotometric determination of copper(II) and nickel(II) in edible oils and seeds  

Microsoft Academic Search

The analytical properties of 1-phenyl-1,2-propanedione-2-oxime thiosemi-carbazone (PPDOT) are described for the first time. The reagent gives colour reactions with copper(II) and nickel(II) in sodium acetate-acetic acid buffer medium. The copper complex shows maximum absorbance at 465 nm while the nickel complex at 395 nm. Therefore, these colour reactions have been advantageously used for the simultaneous spectrophotometric determination of copper(II) and

K. Hussain Reddy; N. B. L Prasad; T. Sreenivasulu Reddy

2003-01-01

192

Synthesis and structural studies of novel Co(III) ternary complexes containing N(4)-substituted thiosemicarbazones of 2-hydroxyacetophenone and heterocyclic bases  

Microsoft Academic Search

An interesting series of eight neutral ternary Co(III) complexes of 2-hydroxyacetophenone N(4)-substituted thiosemicarbazones (H2L), bidentate heterocyclic bases 2,2?-bipyridine (bipy)\\/1,10-phenanthroline (phen) and azide with a general formula [MLB(N3)] were prepared. The complexes were characterized by means of spectroscopic methods. The coordination geometry around Co(III) in all the complexes is distorted octahedral with one dibasic tridentate ligand L2?, one bidentate heterocyclic base

Rohith P John; A Sreekanth; Maliyeckal R Prathapachandra Kurup; Shaikh M Mobin

2002-01-01

193

Preconcentration of Some Trace Metal Ions from Drinking and Tap Water Samples by Sorption on Amberlite XAD?4 after Complexation with Di?2?Pyridyl Ketone Thiosemicarbazone  

Microsoft Academic Search

A method was established for enrichment of trace levels of Co(II), Ni(II), Fe(II), and Cu(II) ions in aqueous solutions. These metals were quantitatively retained on an Amberlite XAD?4 column, after complexation with di?2?pyridyl ketone thiosemicarbazone (DPKT). After elution with 1 M HNO3 in acetone, concentration of metals were measured by atomic absorption spectrometry. The effect of major cations of drinking and

Bürge A?ç?; Güzin Alpdo?an; S?d?ka Sungur

2006-01-01

194

Phase I study of the ribonucleotide reductase inhibitor 3-aminopyridine-2-carboxaldehyde-thiosemicarbazone (3AP) in combination with high dose cytarabine in patients with advanced myeloid leukemia  

Microsoft Academic Search

Summary  \\u000a Purpose: This Phase I dose escalation study was based on the hypothesis that the addition of 3-aminopyridine-2-carboxaldehyde-thiosemicarbazone\\u000a (3-AP) to cytarabine would enhance cytarabine cytotoxicity. The primary objective of the study was to establish the maximum\\u000a tolerated dose of 3-AP when given in combination with a fixed dose of cytarabine. Experimental design: Twenty-five patients with relapsed or refractory myeloid leukemia

Olatoyosi M. Odenike; Richard A. Larson; Devika Gajria; M. Eileen Dolan; Shannon M. Delaney; Theodore G. Karrison; Mark J. Ratain; Wendy Stock

2008-01-01

195

PAN811 (3Aminopyridine2-carboxaldehyde thiosemicarbazone), a novel neuroprotectant, elicits its function in primary neuronal cultures by up-regulating Bcl2 expression  

Microsoft Academic Search

Neurotoxicity in primary neurons was induced using hypoxia\\/hypoglycemia (H\\/H), veratridine (10?M), staurosporine (1?M) or glutamate (100?M), which resulted in 72%, 67%, 75% and 66% neuronal injury, respectively. 3-Aminopyridine-2-carboxaldehyde thiosemicarbazone (PAN-811; 10?M; Panacea Pharmaceuticals, Gaithersburg, MD) pretreatment for 24 h provided maximal neuroprotection of 89%, 42%, 47% and 89% against these toxicities, respectively. Glutamate or H\\/H treatment of cells increased cytosolic

R.-W. Chen; C. Yao; X. C. M. Lu; Z.-G. Jiang; R. Whipple; Z. Liao; H. A. Ghanbari; B. Almassian; F. C. Tortella; J. R. Dave

2005-01-01

196

Transition metal complexes with thiosemicarbazide-based ligands. Part LVI: Nickel(II) complex with 1,3-diphenylpyrazole-4-carboxaldehyde thiosemicarbazone and unusually deformed coordination geometry  

Microsoft Academic Search

Synthesis of a new nickel(II) complex, [Ni(Ph2PzTSC-H)2] with 1,3-diphenylpyrazole-4-carboxaldehyde thiosemicarbazone (Ph2PzTSC), is described. The compounds have been characterized by elemental and thermal analysis, molar conductivity and spectral (UV–Vis, IR, 1H NMR, and 13C NMR) measurements. In the case of complex the magnetic measurement has been also performed. Crystal and molecular structures of both the free ligand and the complex have

Vukadin M. Leovac; Sla?ana B. Novakovi?; Goran A. Bogdanovi?; Milan D. Joksovi?; Katalin Mészáros Szécsényi; Valerija I. ?ešljevi?

2007-01-01

197

Electronic absorption study on acid–base equilibria for some pyrimidine derivatives containing semi- and thiosemicarbazone moiety  

Microsoft Academic Search

The UV–vis spectra of recently synthesized 5-benzoyl-1-(methylphenylmethyleneamino)-4-phenyl-1H-pyrimidine-2-one, (I), and 5-benzoyl-1-(methylphenylmethyleneamino)-4-phenyl-1H-pyrimidine-2-thione, (II) were studied in aqueous methanol (5%, v\\/v methanol). The nature of the electronic transitions and the roles of carbonyl oxygen of I and thiocarbonyl sulfur of II on the behavior of UV–vis spectra were discussed.Acid–base equilibria of the compounds against varying pH and pKa values related equilibria were determined

H. Kiliç

2010-01-01

198

Electronic absorption study on acid-base equilibria for some pyrimidine derivatives containing semi- and thiosemicarbazone moiety.  

PubMed

The UV-vis spectra of recently synthesized 5-benzoyl-1-(methylphenylmethyleneamino)-4-phenyl-1H-pyrimidine-2-one, (I), and 5-benzoyl-1-(methylphenylmethyleneamino)-4-phenyl-1H-pyrimidine-2-thione, (II) were studied in aqueous methanol (5%, v/v methanol). The nature of the electronic transitions and the roles of carbonyl oxygen of I and thiocarbonyl sulfur of II on the behavior of UV-vis spectra were discussed. Acid-base equilibria of the compounds against varying pH and pK(a) values related equilibria were determined at an ionic strength of 0.10 M by using the Henderson-Haselbalch equation. The mean acidity constants for the protonated forms of the compounds were determined as pK(a1)=5.121, pK(a2)=7.929 and pK(a3)=11.130 for I and pK(a1)=4.684, pK(a2)=7.245 and pK(a3)=10.630 for II. The preferred dissociation mechanisms were discussed based on UV-vis data and a mechanism was proposed for each compound. PMID:20018555

Kiliç, H

2009-11-24

199

Synthesis and characterization of new metal complexes of thiosemicarbazone derived from 4-phenyl-3-thiosemicarbazide and chromone-3-carboxaldehyde  

Microsoft Academic Search

Summary The reaction between chromone-3-carboxaldehyde-4-phenylthiosemicarbazone (HCPT) and some hydrated metal salts of CoII, NiII and CuII give complexes of the type [Cu(HCPT)Cl2],[Cu(CPT)BrH2O],[Cu(CPT)2]·2H2O, [Ni(CPT)2(H2O)2]·2H2O, [Co(CPT)2(OAc)] and [Co(CPT)2(H2O)2]X·2H2O (where X=Cl or Br). The metal complexes were characterized by elemental analyses, molar conductivities, and spectal (i.r. and visible) and magnetic studies. I.r. spectra show that the HCPT coordinates in the thione or thiol

Kamal M. Ibrahim; Magdy M. Bekheit

1988-01-01

200

Selective oxidation of toluene to benzaldehyde by O{sub 2} with visible light in barium(2+)- and calcium(2+)-exchanged zeolite Y  

SciTech Connect

High selectivity has been demonstrted upon visible light induced oxygenation of toluene to benzaldehyde in alkaline earth exchanged zeolite Y. We attribute the tight product control to mainly two factors. One is access to the C{sub 6}H{sub 5}CH{sub 3}-O{sub 2} excited charge-transfer state by light of sufficiently long wavelength to prevent loss of product control by photofragmentation of primary products or by homolysis of the proposed hydroperoxide intermediate. The second is confinement of benzyl/HO{sub 2} radical pairs to the zeolite matrix cage, which suppresses indiscriminate attack of these radicals and forces them to combine. The Co{sup 3+}-catalyzed radical oxidation of toluene by O{sub 2} in solution used currently in an industrial process for benzaldehyde synthesis lacks this selectivity, mainly because of continued oxidation of the aldehyde to benzoic acid. 24 refs., 2 figs.

Sun, H.; Blatter, F.; Frei, H. [Lawrence Berkeley Lab., CA (United States)

1994-08-24

201

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

202

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

PubMed

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. PMID:22502535

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

2012-04-14

203

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

204

A laccase of Fomes durissimus MTCC-1173 and its role in the conversion of methylbenzene to benzaldehyde.  

PubMed

A laccase has been purified from the liquid culture growth medium containing bagasse particles of Fomes durissimus. The method involved concentration of the culture filtrate by ultrafiltration and anion exchange chromatography on diethyl aminoethyl cellulose. The sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and native polyacrylamide gel electrophoresis both gave single protein band indicating that the enzyme preparation was pure. The molecular mass of the purified laccase determined from SDS-PAGE analysis was 75 kDa. Using 2,6-dimethoxyphenol as the substrate, the determined K (m) and k (cat) values of the laccase are 182 ?M and 0.35 s(-1), respectively, giving a k (cat)/K (m) value of 1.92?×?10(3) M(-1)?s(-1). The pH and temperature optimum were 4.0 and 35 °C, respectively. The purified laccase has yellow colour and does not show absorption band around 610 nm found in blue laccases. Moreover, it transformed methylbenzene to benzaldehyde in the absence of mediator molecules, property exhibited by yellow laccases. PMID:22081331

Sahay, R; Yadav, R S S; Yadava, Sudha; Yadav, K D S

2011-11-12

205

Effects of pulse feeding of beet molasses on recombinant benzaldehyde lyase production by Escherichia coli BL21(DE3).  

PubMed

The effect of fed-batch operation (FBO) strategy was investigated using pretreated-beet molasses, containing galactose that induces the lac promoter, on benzaldehyde lyase (BAL) production by recombinant Escherichia coli BL21(DE3)pLySs. After batch cultivation with 30 g l(-1) pretreated-beet molasses consisting of 7.5 g l(-1) glucose and 7.5 g l(-1) fructose, three FBO strategies were applied at dissolved oxygen (=40%) cascade to air-flow rate. In FBO1 when air-flow rate decreased considerably, feed was given to the system in pulses in such a way that pretreated-beet molasses concentration increased by 10 kg m(-3) (containing 2.5 g l(-1) glucose+2.5 g l(-1) fructose); however, decrease in air-flow rate demonstrated only the absence of glucose but not fructose. Thus, in FBO2 when fructose and glucose were completely utilized, pretreated-beet molasses was pulse-fed and its concentration increased by 10 g l(-1). In FBO3 with the decreased amount of pretreated-beet molasses (6 g l(-1)), shift response time from glucose to fructose consumption was avoided, and glucose and fructose consumptions were well correlated with air-flow rate, and the highest CX (8.04 g l(-1)) and BAL (2,315 U ml(-1)) production were obtained (t=24 h) with the highest substrate yield on cell and product formation. PMID:19547969

Calik, Pinar; Levent, Hande

2009-06-23

206

Coordination Compounds of Rare Earth Chlorides with the Schiff Base Derived from Vanillin and 2Naphthylamine  

Microsoft Academic Search

Coordination compounds of rare earth chlorides with Schiff base derived from vanillin (3-methoxy-4-hydroxy-benzaldehyde) and 2-naphthylamine have been prepared and characterized. The general formula of the coordination compounds, [LnL2Cl2(H20)2] Cl H20 (where Ln - La, Ce, Pr, Nd, Eu, Gd, Dy, Ho, Tm, Lu; L = Schiff base), are based on the elemental analyses, infrared spectra, ultraviolet spectra, Raman Spectra, Molar

Liu Guofa; Zhao Yongnian; Cao Xizhang

1992-01-01

207

Coordination Compounds of Rare Earth Nitrate with Schiff Base Derived from Vanillin and 2Naphthylamine  

Microsoft Academic Search

New coordination coapounds of rare earth nitrates with Schiff base derived from vanillin (3-methoxy-4-hydroxy-benzaldehyde) and 2-naphthylanine having the general formula [LnL2(N03)2] NO3 (where Ln = La, Nd, Sm, Eu, Tb, Dy, Er, Yb, Lu; L = Schiff base) have been prepared and characterized on the basis of elemental analyses, infrared spectra, X-ray photoelectron spectroscopy, molar conductance and thermal analyses.

Liu Guofa; Liu Xiaoxun; Cao Xizhang

1992-01-01

208

A three-component novel synthesis of 1-carbamato-alkyl-2-naphthol derivatives  

Microsoft Academic Search

A new one-pot, efficient three-component condensation of benzaldehydes, 2-naphthol, and carbamates in the presence of silica supported sodium hydrogen sulfate as an effective heterogeneous catalyst for the synthesis of novel 1-carbamato-alkyl-2-naphthol derivatives under solvent-free conditions is described. The present methodology offers several advantages, such as high yields, short reaction times, and very easy workup.

Hamid Reza Shaterian; Asghar Hosseinian; Majid Ghashang

2008-01-01

209

Complexes of Rare Earth Nitrate Schiff Base Derived from O-Vanillin and 2Naphthylamine  

Microsoft Academic Search

Complexes of rare earth nitrates with Schiff bases derived from o-vanillin (2-hydroxy-3-methoxy-benzaldehyde) and 2-naphthylamine have been prepared and characterized. The complexes have been given the general formula [LnL2 (NO3)] (NO3)2 (where Ln = La, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, Lu; L = Schiff base) on the basis of elemental analyses, molar conductance, infrared spectra,

Liu Guofa; Na Chongwu; Li Bin

1990-01-01

210

Copper(II) and nickel(II) complexes of benzyloxybenzaldehyde-4-phenyl-3-thiosemicarbazone: Synthesis, characterization and biological activity  

NASA Astrophysics Data System (ADS)

Benzyloxybenzaldehyde-4-phenyl-3-thiosemicarbazone ligand (L) has been synthesized from benzyloxybenzaldehyde and 4-phenyl-3-thiosemicarbazide. Complexes of this ligand with chlorides of Cu(II) and Ni(II) have been prepared. The structure of the ligand (L) is proposed based on elemental analysis, IR and 1H NMR spectra. Its complexes with Cu(II) and Ni(II) ions are characterized from the studies of electronic as well as EPR spectra. On the basis of electronic and EPR studies, rhombically distorted octahedral structure has been proposed for Cu(II) complex while the Ni(II) complex has been found to acquire an octahedral structure. The ligand and their metal complexes have been tested in vitro for their biological effects. Their antibacterial activities against Gram-negative bacteria ( Escherichia coli and Klebsiella pneumoniae) and Gram-positive bacteria ( Staphylococcus aureus and Bacillus subtilis) have been investigated. The prepared metal complexes exhibit higher antibacterial activities than the parent ligand. The in vitro antioxidant activity of free ligand and its metal(II) complexes have also been investigated and the results however reveal that the ligand exhibits greater antioxidant activity than its complexes.

Prathima, B.; Subba Rao, Y.; Adinarayana Reddy, S.; Reddy, Y. P.; Varada Reddy, A.

2010-09-01

211

Growth, spectral, optical, thermal, crystallization perfection and nonlinear optical studies of novel nonlinear optical crystal--urea thiosemicarbazone monohydrate.  

PubMed

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 (1)H 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. PMID:22391224

Hanumantharao, Redrothu; Kalainathan, S; Bhagavannarayana, G

2012-02-13

212

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

213

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

2011-05-19

214

Diorganotin Complexes of a Thiosemicarbazone, Synthesis: Properties, X-Ray Crystal Structure, and Antiproliferative Activity of Diorganotin Complexes  

PubMed Central

The synthesis and spectral characterization of novel diorganotin complexes with 3-hydroxypyridine-2-carbaldehyde thiosemicarbazone, H2L(1), [SnMe2(L)] (2), [SnBu2(L)] (3), and [SnPh2(L)] (4) are reported. The single-crystal X-ray structure of complex [SnPh2(L)(DMSO)] (5) shows that the ligand is doubly deprotonated and is coordinated as tridentate ligand. The six coordination number is completed by two carbon atoms of phenyl groups. There are two similar monomers 5a (Sn1) and 5b (Sn51) in the asymmetric unit. The monomers 5a and 5b are linked through intermolecular hydrogen bonds of N–H–O and C–H–S type. C–H ? ?, intermolecular interactions, intra- and intermolecular hydrogen bonds stabilize this structure and leads to aggregation and a supramolecular assembly. The IR and NMR (1H, 13C and 119Sn) spectroscopic data of the complexes are reported. The in vitro cytotoxic activity has been evaluated against the cells of three human cancer cell lines: MCF-7 (human breast cancer cell line), T-24 (bladder cancer cell line), A-549 (nonsmall cell lung carcinoma) and a mouse L-929 (a fibroblast-like cell line cloned from strain L). Compounds 1, 3, and 4 were found active against all four cell lines. Selectivity was observed for complexes 3 and 4 which were found especially active against MCF-7 and T-24 cancer cell lines.

Wiecek, Joanna; Kovala-Demertzi, Dimitra; Ciunik, Zbigniew; Zervou, Maria; Demertzis, Mavroudis A.

2010-01-01

215

Complex formation between uranyl and various thiosemicarbazide derivatives  

SciTech Connect

Complex formation between hexavalent uranium and salicylaldehyde thiosemicarbazone (H/sub 2/L), salicylaldehyde S-methyl-isothiosemicarbazone (H/sub 2/Q), S-methyl-N/sub 1/,N/sub 4/-bis(salicylidene)isothiosemicarbazide(H/sub 2/Z), and thiosemicarbazidodiacetic acid (H/sub 2/R) has been studied spectrophotometrically in solution. Stability constants for complexes having the composition UO/sub 2/A have been calculated. Solid uranyl derivatives having the composition UO/sub 2/L x 2H/sub 2/O, UO/sub 2/Q x 2H/sub 2/O, UO/sub 2/Z x 2H/sub 2/O, and UO/sub 2/R x 2H/sub 2/O have been obtained. These derivatives were isolated and their IR spectroscopic behavior and thermal properties were investigated.

Chuguryan, D.G.; Dzyubenko, V.I.

1987-01-01

216

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

217

The anticancer thiosemicarbazones Dp44mT and triapine lack inhibitory effects as catalytic inhibitors or poisons of DNA topoisomerase II?  

PubMed Central

The thiosemicarbazones Dp44mT (di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone) and triapine have potent antiproliferative activity and have been evaluated as anticancer agents. While these compounds strongly bind iron and copper, their mechanism(s) of action are incompletely understood. A recent report (Rao et al., Cancer Research 69:948-957, 2009) suggested that Dp44mT may, in part, exert its cytotoxicity through poisoning of DNA topoisomerase II?. In the present report, a variety of assays were used to determine whether Dp44mT and triapine target topoisomerase II?. Neither compound inhibited topoisomerase II? decatenation or induced cleavage of pBR322 DNA in the presence of enzyme. In cells, Dp44mT did not stabilize topoisomerase II? covalent binding to DNA using an immunoblot band depletion assay, an ICE (immunodetection of complexes of enzyme-to-DNA) assay, and a protein-DNA covalent complex forming assay. Dp44mT did not display cross resistance to etoposide resistant K562 cells containing reduced topoisomerase II? levels. Synchronized Dp44mT-treated CHO cells did not display a G2/M cell cycle block expected of a topoisomerase II inhibitor. A COMPARE analysis of Dp44mT using the NCI 60-cell line data indicated that inhibition of cell growth was poorly correlated with DNA topoisomerase II? mRNA levels. In summary, we found no support for the conclusion that Dp44mT inhibits cell growth through the targeting of topoisomerase II?. Since clinical trials of triapine are underway, it will be important to better understand the intracellular targeting and mechanisms of action of the thiosemicarbazones to support forward development of these agents and newer analogs.

Yalowich, Jack C.; Wu, Xing; Zhang, Rui; Kanagasabai, Ragu; Hornbaker, Marissa; Hasinoff, Brian B.

2012-01-01

218

The anticancer thiosemicarbazones Dp44mT and triapine lack inhibitory effects as catalytic inhibitors or poisons of DNA topoisomerase II?.  

PubMed

The thiosemicarbazones Dp44mT (di-2-pyridylketone-4,4-dimethyl-3-thiosemicarbazone) and triapine have potent antiproliferative activity and have been evaluated as anticancer agents. While these compounds strongly bind iron and copper, their mechanism(s) of action are incompletely understood. A recent report (Rao et al., Cancer Research 69:948-57, 2009) suggested that Dp44mT may, in part, exert its cytotoxicity through poisoning of DNA topoisomerase II?. In the present report, a variety of assays were used to determine whether Dp44mT and triapine target topoisomerase II?. Neither of these compounds inhibited topoisomerase II? decatenation or induced cleavage of pBR322 DNA in the presence of enzyme. In cells, Dp44mT did not stabilize topoisomerase II? covalent binding to DNA using an immunoblot band depletion assay, an ICE (immunodetection of complexes of enzyme-to-DNA) assay, and a protein-DNA covalent complex forming assay. Dp44mT did not display cross resistance to etoposide resistant K562 cells containing reduced topoisomerase II? levels. Synchronized Dp44mT-treated CHO cells did not display a G2/M cell cycle block expected of a topoisomerase II inhibitor. A COMPARE analysis of Dp44mT using the NCI 60-cell line data indicated that inhibition of cell growth was poorly correlated with DNA topoisomerase II? mRNA levels. In summary, we found no support for the conclusion that Dp44mT inhibits cell growth through the targeting of topoisomerase II?. Since clinical trials of triapine are underway, it will be important to better understand the intracellular targeting and mechanisms of action of the thiosemicarbazones to support forward development of these agents and newer analogs. PMID:22503743

Yalowich, Jack C; Wu, Xing; Zhang, Rui; Kanagasabai, Ragu; Hornbaker, Marisa; Hasinoff, Brian B

2012-04-04

219

Ruthenium(II) complexes of NSO donor ligands in the form of ring-substituted 4-phenyl-thiosemicarbazones of salicylaldehyde and o-hydroxyacetophenone  

Microsoft Academic Search

This work describes the preparation and characterisation of ruthenium(II) complexes of several ONS donor ligands in the form of ring-substituted 4-phenylthiosemicarbazones of salicylaldehyde and o-hydroxyacetophenone. Reactions of these thiosemicarbazone ligands with [Ru(PPh3)3]Cl2 in refluxing MeOH furnished ruthenium(II) complexes of general formula [Ru(PPh3)2(LH)Cl] where the ligands acted as monoanionic tridentate ONS donors attached to the ruthenium(II) acceptor centre through the deprotonated

Parbati Sengupta; Rupam Dinda; Saktiprosad Ghosh

2002-01-01

220

The relationship between ligand structures and their Co and Ni complexes: Synthesis and characterization of novel dimeric Co\\/Co complexes of bis(thiosemicarbazone)  

Microsoft Academic Search

4,6-Diacetylresorcinol serves as a starting point for the generation of multidentate S\\/N\\/O or O\\/N\\/O symmetrical chelating agents by condensation with thiosemicarbazide or semicarbazide to yield the corresponding bis(thiosemicarbazone) H4L or bis(semicarbazone) H4L, respectively. Reaction of H4L and H4L with M(NO3)2·6H2O (M?=?Co or Ni) afforded dimeric complexes for H4L and binuclear complexes for H4L, revealing the tendency of S to form

H. S. Seleem; A. A. Emara; M. Shebl

2005-01-01

221

Synthesis, crystal structure and characterization of 3-thiophene aldehyde thiosemicarbazone and its complexes with cobalt(II), nickel(II) and copper(II)  

Microsoft Academic Search

The reaction of cobalt(II), nickel(II), copper(II) chlorides and bromides with 3-thiophene aldehyde thiosemicarbazone (3TTSCH) leads to the formation of a series of new complexes: [Co(3TTSC)2], [Ni(3TTSC)2], [CuCl(3TTSC)]2, [CuBr(3TTSC)]2 and [CuBr2(3TTSCH)]. The crystal structures of the free ligand and of the compound [Ni(3TTSC)2] have been determined by X-ray diffraction methods. For all these complexes, the central ion is coordinated through the

Kusaï Alomar; Mustayeen A. Khan; Magali Allain; Gilles Bouet

2009-01-01

222

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

Microsoft Academic Search

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, 1H NMR, and electronic spectra. The crystal structures of the compound [ZnCl2(3TTSCH)2] and [CdBr2(3TTSCH)2] have been determined by X-ray diffraction methods. For the complexes [ZnCl2(3TTSCH)2] and [CdBr2(3TTSCH)2], the central

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

2010-01-01

223

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

Microsoft Academic Search

Summary  3-Aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP, Triapine®) is a novel small molecule inhibitor of ribonucleotide\\u000a reductase (RR) with clinical signs of activity in pancreatic cancer. Therefore, the Phase 2 Consortium (P2C) initiated a trial\\u000a (two single stage studies with planned interim analysis) of 3-AP at 96 mg\\/m2 intravenously days 1–4 and 15–18 of a 28-day cycle in both chemotherapy-naive and gemcitabine-refractory (GR) patients with

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

2008-01-01

224

Synthesis, spectral studies and in vitro assessment for antiamoebic activity of new cyclooctadiene ruthenium(II) complexes with 5-nitrothiophene-2-carboxaldehyde thiosemicarbazones  

Microsoft Academic Search

We report here the synthesis, characterization and in vitro antiamoebic activity of 5-nitrothiophene-2-carboxaldehyde thiosemicarbazones (TSC), 1–5, and their bidentate complexes [Ru(?4-C8H12)(TSC)Cl2] 1a–5a. The biological studies of these compounds were investigated against HK-9 strain of Entamoeba histolytica and the concentration causing 50% cell growth inhibition (IC50) was calculated in the micromolar range. The ligands exhibited antiamoebic activity in the range (2.05–5.29?M).

Shailendra Singh; Fareeda Athar; Amir Azam

2005-01-01

225

A Phase II study of 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3AP) and gemcitabine in advanced pancreatic carcinoma. A trial of the Princess Margaret Hospital Phase II consortium  

Microsoft Academic Search

Summary  3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP, Triapine®, Vion Pharmaceuticals, New Haven, CT) is an inhibitor\\u000a of the M2 subunit of ribonucleotide reductase (RR). Preclinical testing demonstrates synergy between 3-AP and gemcitabine.\\u000a Phase I studies of the combination have suggested tolerability and some initial evidence of efficacy. Therefore, a phase II\\u000a study of gemcitabine plus 3-AP in advanced pancreatic carcinoma was undertaken.\\u000a \\u000a In this

M. J. Mackenzie; D. Saltman; H. Hirte; J. Low; C. Johnson; G. Pond; M. J. Moore

2007-01-01

226

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

227

Synthesis, characterization antibacterial and antiproliferative activity of novel Cu(II) and Pd(II) complexes with 2-hydroxy-8-R-tricyclo[7.3.1.0.(2,7)]tridecane-13-one thiosemicarbazone.  

PubMed

Synthesis and biological activity investigation of complex compounds of Cu(II) are challenging issues because of the metal is not a xenobiotic one and the activity of ligands could be modulated by complexation. Complex combinations of Cu(II) and Pd(II) with thiosemicarbazone derivatives of 2-hydroxy-8-R-tricyclo[7.3.1.0.(2,7)]tridecane-13-one (where R=C(3)H(7), C(4)H(3)O) were synthesized. The characterization of the ligands and the newly formed compounds was done by (1)H NMR, (13)C NMR, UV-vis, IR, ESR spectroscopy, elemental analysis, molar electric conductibility and thermal studies. Experiments performed to identify the structures proved that the ligands coordinate to metal ions in different ways - neutral bidentate or mononegative bidentate. Also, if copper(II) acetate, copper(II) nitrate, copper(II) chloride and copper(II) thiocyanate were used, the ligands coordinated in a mononegative bidentate fashion. If copper(II) sulfate was used, the ligands coordinated in a neutral bidentate fashion. The biological activity for the copper(II) synthesized compounds was assessed in terms of antibacterial or antiproliferative activity. The antibacterial activity of the complexes against Staphylococcus aureus var. Oxford 6538, Escherichia coli ATCC 10536, Klebsielle pneumoniae ATCC 100131 and Candida albicans ATCC 10231 strains was studied and compared with that of free ligands. The effect of complex compounds on the proliferation of HeLa cells was tested. For all tested complexes an antiproliferative activity was noted at concentrations higher than 1 microM, but lower than 10 microM. Therefore, complex compounds of copper(II) were synthesized, structurally characterized and tested for biological activity, proving both antibacterial and antiproliferative activity. PMID:20096975

Rosu, Tudor; Pahontu, Elena; Pasculescu, Simona; Georgescu, Rodica; Stanica, Nicolae; Curaj, Adelina; Popescu, Alexandra; Leabu, Mircea

2010-01-22

228

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

229

3-Eth-oxy-2-hy-droxy-benzaldehyde 2,4-di-nitro-phenylhydrazone N,N-di-methyl-formamide monosolvate.  

PubMed

The Schiff base of the title compound, C(15)H(14)N(4)O(6)·C(3)H(7)NO, was obtained from the condensation reaction of 3-eth-oxy-2-hy-droxy-benzaldehyde and 2,4-dinitro-phenyl-hydrazine. The dihedral angle between the benzene rings is 3.05?(10)° and intra-molecular N-H?O and O-H?O hydrogen bonds generate S(6) and S(5) ring motifs, respectively. In the crystal, the Schiff base and dimethyl-formamide solvent mol-ecules are linked by an O-H?O hydrogen bond. PMID:21588577

Zhao, Lin-Xiu; Cui, Jian-Lan; Cao, Duan-Lin

2010-08-04

230

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

2011-11-21

231

The synthesis and biological evaluation of some caffeic acid amide derivatives: E-2-Cyano-(3-substituted phenyl)acrylamides  

Microsoft Academic Search

A series of caffeic acid amide derivatives 2-cyano-(3-substituted phenyl)acrylamides were synthesized via Knoevenogal condensation of substituted benzaldehydes with cyanoacetamides. The structure of compound 1f was determined as E-isomer by X-ray diffractive analysis. The biological screening tests in vitro showed that compound 1b has obvious inhibitory activities against human gastric carcinoma cell line BGC-823, human nasopharyngeal carcinoma cell line KB and

Wei Zhou; Hai-bo Li; Chun-nian Xia; Xian-ming Zheng; Wei-xiao Hu

2009-01-01

232

Some polyhydroxy azo–azomethine derivatives of salicylaldehyde: Synthesis, characterization, spectroscopic, molecular structure and antimicrobial activity studies  

Microsoft Academic Search

Some new substituted polyhydroxy azo–azomethine compounds were prepared by reaction of tris(hydroxymethyl)aminomethane with (E)-2-hydroxy-5-(phenyldiazenyl) benzaldehyde and its substituted derivatives. The structures of azo and azo–azomethine compounds were determined by IR, UV–vis, 1H NMR and 13C NMR spectroscopic techniques, and\\/or X-ray diffraction studies. According to IR spectra, all azo–azomethine compounds adopt keto form in solid state. UV–vis analysis has shown the

Mustafa Odabasoglu; Çigdem Albayrak; Resit Özkanca; Fatma Zehra Aykan; Peter Lonecke

2007-01-01

233

Synthesis, Characterisation, Electrochemistry and Biological Activity of Ruthenium(III) Complexes Containing N.S Donor Ligands and Triphenylphosphine or Triphenylarsine  

Microsoft Academic Search

Several new hexa-coordinated low-spin d ruthenium(III) complexes of the type [RuX2(TSC)(EPh3)2] (where X = Cl or Br; H-TSC = benzaldehyde thiosemicarbazone, cinnamaldehyde thiosemicarbazone, thiophene-2-carboxaldehyde thiosemicarbazone and 2-furaldehyde thiosemicarbazone, E = P or As) have been synthesised by the reactions of [RuX3(EPh3)3] or [RuBr3(PPh3)2(MeOH)] with the various thiosemicarbazones. All the new complexes were characterised using various physico-chemical methods such as elemental

N. Dharmaraj; K. Natarajan

1997-01-01

234

Comparison of benzyl alcohol dehydrogenases and benzaldehyde dehydrogenases from the benzyl alcohol and mandelate pathways in Acinetobacter calcoaceticus and from the TOL-plasmid-encoded toluene pathway in Pseudomonas putida. N-terminal amino acid sequences, amino acid compositions and immunological cross-reactions.  

PubMed Central

1. N-Terminal sequences were determined for benzyl alcohol dehydrogenase, benzaldehyde dehydrogenase I and benzaldehyde dehydrogenase II from Acinetobacter calcoaceticus N.C.I.B. 8250, benzyl alcohol dehydrogenase and benzaldehyde dehydrogenase encoded by the TOL plasmid pWW53 in Pseudomonas putida MT53 and yeast K(+)-activated aldehyde dehydrogenase. Comprehensive details of the sequence determinations have been deposited as Supplementary Publication SUP 50161 (5 pages) at the British Library Document Supply Centre, Boston Spa. Wetherby. West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1991) 273. 5. The extent of sequence similarity suggests that the benzyl alcohol dehydrogenases are related to each other and also to established members of the family of long-chain Zn2(+)-dependent alcohol dehydrogenases. Benzaldehyde dehydrogenase II from Acinetobacter appears to be related to the Pseudomonas TOL-plasmid-encoded benzaldehyde dehydrogenase. The yeast K(+)-activated aldehyde dehydrogenase has similarity of sequence with the mammalian liver cytoplasmic class of aldehyde dehydrogenases but not with any of the Acinetobacter or Pseudomonas enzymes. 2. Antisera were raised in rabbits against the three Acinetobacter enzymes and both of the Pseudomonas enzymes, and the extents of the cross-reactions were determined by immunoprecipitation assays with native antigens and by immunoblotting with SDS-denatured antigens. Cross-reactions were detected between the alcohol dehydrogenases and also among the aldehyde dehydrogenases. This confirms the interpretation of the N-terminal sequence comparisons and also indicates that benzaldehyde dehydrogenase I from Acinetobacter may be related to the other two benzaldehyde dehydrogenases. 3. The amino acid compositions of the Acinetobacter and the Pseudomonas enzymes were determined and the numbers of amino acid residues per subunit were calculated to be: benzyl alcohol dehydrogenase and TOL-plasmid-encoded benzyl alcohol dehydrogenase, 381; benzaldehyde dehydrogenase I and benzaldehyde dehydrogenase II, 525; TOL-plasmid-encoded benzaldehyde dehydrogenase, 538.

Chalmers, R M; Keen, J N; Fewson, C A

1991-01-01

235

Microbial Assay of Ruthenium(II) Thiosemicarbazone Complexes: Synthesis, Spectral Characterization, and Electrochemistry  

Microsoft Academic Search

Ruthenium complexes are synthesized with Schiff bases derived from salicylaldehyde\\/o-hydroxyacetophenone\\/o-vanillin\\/2-hydroxy-1-naphthaldehyde with thiosemicarbazide and thiophenecarboxaldehyde. Ruthenium coordinates in a tetradendate manner with these N2O2 donor ligands, which are characterized by elemental analysis, IR, electronic, and H NMR, C NMR spectral studies. The elemental analysis suggests the stoichiometry to be 1:1 (metal:ligand). The redox behavior of the complexes has been investigated by

Gunasekaran Raja; Nagarajan Sathya; Chinnasamy Jayabalakrishnan

2011-01-01

236

Synthesis and Characterization of Tin(IV) Complexes of Biologically Active Thiosemicarbazones  

Microsoft Academic Search

Several substitution products of organotin(IV) chloride with biologically active schiff bases derived by the condensation of furfuraldehyde, thiophene-2-aldehyde, indol-3-carboxyaldehyde and cinnamaldehyde with thiosemicarbazide and having the general formulae R2SnCl (TSCZ) and R2 Sn (TSCZ)2 (where R = CH3 and TSCZ = anion of Schiff base) have been synthesised. These have been characterized by elemental analyses, molecular weight determinations and conductivity

Kiran; R. V. Singh; J. P. Tandon

1986-01-01

237

Synthesis and characterization of some biologically active ruthenium(II) complexes of thiosemicarbazones of pyridine 2-aldehyde and thiophene 2-aldehyde involving some ring substituted 4-phenylthiosemicarbazides and 4-cyclohexylthiosemicarbazide. Crystal structure of cis-[Ru(PPh 3) 2(L 6H) 2](ClO 4) 2·2H 2O [L 6H=4-(cyclohexyl) thiosemicarbazone of pyridine 2-aldehyde  

Microsoft Academic Search

A series of ruthenium(II) complexes of potentially NNS tridentate but functionally NS bidentate chelating ligands in the form of 4-substituted 4-phenyl and 4-cyclohexyl thiosemicarbazones of pyridine 2-aldehyde and thiophene 2-aldehyde (LH) have been synthesized using Ru(PPh3)3Cl2 as the starting material. The complexes are of the general formula [Ru(PPh3)2(LH)2]X2, [L1H, L2H, L3H, L4H, L5H and L6H are 4-(p-fluorophenyl), 4-(p-chlorophenyl) 4-(p-iodophenyl), 4-(p-hydroxyphenyl),

Parbati Sengupta; Rupam Dinda; Saktiprosad Ghosh; William S Sheldrick

2003-01-01

238

Synthesis and antimicrobial evaluation of some new thienopyrimidine derivatives.  

PubMed

Reaction of heteroaromatic o-aminonitrile with ethyl N-[bis(methylthio)methylene]amino acetate resulted in annelation of a thieno[3,2-e]imidazo[1,2-c]pyrimidine moiety in a one step process. [1,2,4]Triazolo[4,3-c]thieno- [3,2-e]pyrimidine derivatives were prepared by initial treatment of o-aminonitrile with carbon disulfide, followed by methylation with methyl iodide and subsequent reaction with benzhydrazide and thiosemicarbazide, respectively. Hydrazinothieno[2,3-d]pyrimidine was prepared by cyclization of heteroaromatic o-aminoester with formamide, followed by chlorination and subsequent displacement with hydrazine. Treatment of the hydrazino derivative with acetylacetone, benzaldehyde and acetic anhydride afforded pyrazolylpyrimidine, benzylidenehydrazonopyrimidine and triazolopyrimidine derivatives, respectively. Some of these derivatives exhibited pronounced antimicrobial activity. PMID:19839136

Bhuiyan, M D Mosharef Hossain; Rahman, Khandker M D Mizanur; Hossain, M D Kamrul; Rahim, Abdur; Hossain, Mohammed Ismail; Abu Naser, Mohammad

2006-12-01

239

OZONE REACTION WITH N-ALDEHYDES (N=4-10), BENZALDEHYDE, ETHANOL, ISOPROPANOL, AND N-PROPANOL ADSORBED ON A DUAL-BED GRAPHITIZED CARBON/CARBON MOLECULAR SIEVE ADSORBENT CARTRIDGE  

EPA Science Inventory

Ozone reacts with n-aldehydes (n = 4 - 10), benzaldehyde, ethanol, isopropanol, and n-propanol adsorbed on a dual-bed graphitized carbon/carbon molecular sieve adsorbent cartridge. Destruction of n-aldehydes increases with n number and with ozone concentration. In some samp...

240

Synthesis and calcium channel antagonist activity of novel 1,4-dihydropyridine derivatives possessing 4-pyrone moieties  

Microsoft Academic Search

New 1,4-dihydropyridine derivatives were synthesized by introducing 4-pyrone ring systems at the 4-position of the dihydropyridine\\u000a nucleus. These compounds were obtained according to Hantzsch reaction. 4-Pyrone carbaldehydes: 4-(4-oxo-6-phenyl-4H-pyran-2-yl)benzaldehyde 4a, 4-(6-methyl-4-oxo-4H-pyran-2-yl)benzaldehyde 4b, 4-oxo-6-phenyl-4H-pyran-2-carbaldehyde 7a, and 6-methyl-4-oxo-4H-pyran-2-carbaldehyde 7b were synthesized and used in these reactions. Then, the calcium channel blocking activity of some of these compounds were\\u000a evaluated in which they showed weak

Aziz Shahrisa; Ramin Miri; Somayeh Esmati; Mahnaz Saraei; Ahmad Reza Mehdipour; Maryam Sharifi

241

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

2012-06-25

242

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

PubMed

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. PMID:12659904

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

2003-04-01

243

Dearylation with aromatization on cyclocondensation of 4-(dimethyl-amino)benzaldehyde, 2-phenacylaza-heterocycles, and 1,3-[N,C]dinucleophiles  

Microsoft Academic Search

Three-component cyclocondensation involving p-(dimethylamino)benzaldehyde, 2-phenacylazahetero-cycle, and a 1,3-[N,C]-nucleophile\\u000a (3,5-dimethoxyaniline, 6-amino-1,3-dimethylpyrimidine-2,4-dione, 1-amino-3-methyl-5-phenylpyrazole) in boiling acetic acid\\u000a is accompanied by aromatization of the initially formed annelated 4-(p-dimethylaminophenyl)-3-hetaryl-2-phenyl-1,4-dihydropyridines, the direction of which, with splitting off the dimethylaminophenyl\\u000a substituent or its retention, is determined by the basicity of the hetaryl residue and the structure of the second ring, constructed\\u000a on the binucleophile. A possible

I. B. Dzvinchuk

2009-01-01

244

Biological activities of isatin and its derivatives.  

PubMed

Isatin is an endogenous compound identified in humans that possesses a wide range of biological activities. Isatin has anxiogenic, sedative, anticonvulsant activities and acts as a potent antagonist on atrial natriuretic peptide receptors in vitro. A series of p-substituted isatin semicarbazones have shown anticonvulsant activity in MES, scPTZ and scSTY tests. Various isatin-N-Mannich bases of isatin-3-thiosemicarbazones have shown antiviral and tuberculostatic activity. Methisazone is an effective compound against variola and vaccinia viruses. The N-dimethyl and morpholino derivative of 5-methyl isatin and trimethoprim exhibited an EC50 of more than 4.3 and 17.7 mg mL(-1), respectively. Isatin (3-o-nitrophenyl) hydrazone has shown activity against Walker carcinoma-256. Various substituted indolinones showed antitubercular activity against M. tuberculosis H37Rv with MIC ranging from 10-20 microg mL(-1). Isatin derivatives of Mannich bases had fibrinolytic, muscle relaxant, antiallergic, immunosuppressant, and antithrombotic activity. Isatin showed cardioinhibitory effect on frog heart, and hypotensive, respiratory depression and antidiuretic effects. PMID:15907222

Pandeya, Surendra Nath; Smitha, Sivakumar; Jyoti, Mayank; Sridhar, Seshaiah Krishnan

2005-03-01

245

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

2012-01-05

246

Role of substitution at terminal nitrogen of 2-oxo-1,2-dihydroquinoline-3-carbaldehyde thiosemicarbazones on the coordination behavior and structure and biological properties of their palladium(II) complexes.  

PubMed

A series of four new palladium(II) complexes of 2-oxo-1,2-dihydroquinoline-3-carbaldehyde thiosemicarbazones with triphenylphosphine as coligand have been synthesized and characterized by the aid of various spectral techniques. The single-crystal X-ray diffraction studies revealed that the unsubstituted thiosemicarbazone ligand acted as monobasic tridentate (ONS(-)) in the cationic [Pd(H-Qtsc-H)(PPh(3))]Cl complex, whereas the monosubstituted thiosemicarbazone ligands acted as monobasic bidentate (NS(-)) in their respective complexes, [PdCl(H-Qtsc-R)(PPh(3))] (R = Me (2), Et (3), Ph (4)). To ascertain the potentials of the above Pd(II) complexes toward biomolecular interactions, additional experiments involving interaction with calf thymus DNA and bovine serum albumin were carried out. Moreover, all the palladium(II) complexes have been screened for their radical scavenging activity toward DPPH, O(2)(-), OH, and NO radicals. The efficiency of the complexes in arresting the growth of human cervical cancer cells (HeLa), human laryngeal epithelial carcinoma cells (HEp-2), human liver carcinoma cells (Hep G2), and human skin cancer cells (A431) has also been studied along with the cell viability test against the noncancerous NIH 3T3 mouse embryonic fibroblasts cell lines under in vitro conditions. All the in vitro pharmacological evaluation results clearly revealed the relationship between the structure and the activity of the new Pd(II) complexes. PMID:23323516

Ramachandran, Eswaran; Senthil Raja, Duraisamy; Rath, Nigam P; Natarajan, Karuppannan

2013-01-16

247

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

248

2-Benzoylpyridine thiosemicarbazone as a novel reagent for the single pot synthesis of dinuclear Cu(I)-Cu(II) complexes: formation of stable copper(II)-iodide bonds.  

PubMed

2-Benzoylpyridine thiosemicarbazone {R(1)R(2)C(2)=N(2)·N(3)H-C(1)(=S)-N(4)H(2), R(1) = py-N(1), R(2) = Ph; Hbpytsc} with copper(I) iodide in acetonitrile-dichloromethane mixture has formed stable Cu(II)-I bonds in a dark green Cu(II) iodo-bridged dimer, [Cu(2)(II)(?-I)(2)(?(3)-N(1),N(2),S-bpytsc)(2)] 1. Copper(I) bromide also formed similar Cu(II)-Br bonds in a dark green Cu(II) bromo-bridged dimer, [Cu(2)(II)(?-Br)(2)(?(3)-N(1),N(2),S-bpytsc)(2)] 3. The formation of dimers 1 and 3 appears to be due to a proton coupled electron transfer (PCET) process wherein copper(I) loses an electron to form copper(II), and this is accompanied by a loss of -N(3)H proton of Hbpytsc ligand resulting in the formation of anionic bpytsc(-). When copper(I) iodide was reacted with triphenylphosphine (PPh(3)) in acetonitrile followed by the addition of 2-benzoylpyridine thiosemicarbazone in dichloromethane (Cu?:?PPh(3)?:?Hbpytsc in the molar ratio 1:1:1), both Cu(II) dimer 1 and an orange Cu(I) sulfur-bridged dimer, [Cu(2)(I)I(2)(?-S-Hbpytsc)(2)(PPh(3))(2)] 2 were formed. Copper(I) bromide with PPh(3) and Hbpytsc also formed Cu(II) dimer 3 and an orange Cu(I) sulfur-bridged dimer, [Cu(2)(I)Br(2)(?-S-Hbpytsc)(2)(PPh(3))(2)] 4. While complexes 2 and 4 exist as sulfur-bridged Cu(I) dimers, 1 and 3 are halogen-bridged. The central Cu(2)S(2) cores of 2 and 4 as well as Cu(2)X(2) of 1 (X = I) and 3 (X = Br) are parallelograms. One set of Cu(II)-I and Cu(II)-Br bonds are short, while the second set is very long {1, Cu-I, 2.565(1), 3.313(1) Å; 3, Cu-Br, 2.391(1), 3.111(1) Å}. The Cu···Cu separations are long in all four complexes {1, 4.126(1); 2, 3.857(1); 3, 3.227(1); 4, 3.285(1) Å}, more than twice the van der Waals radius of a Cu atom, 2.80 Å. The pyridyl group appears to be necessary for stabilizing the Cu(II)-I bond, as this group can accept ?-electrons from the metal. PMID:22395858

Lobana, Tarlok S; Khanna, Sonia; Butcher, Ray J

2012-03-06

249

Exploring microwave synthesis for co-ordination: synthesis, spectral characterization and comparative study of transition metal complexes with binuclear core derived from 4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one  

Microsoft Academic Search

A series of transition metal complexes of Cu(II), Ni(II), Co(II), Mn(II), Zn(II), Hg(II), and Sn(II) has been synthesized from the Schiff base (L) derived from 4-aminoantipyrine and 4-fluoro-benzaldehyde using traditional synthetic methodology and microwave-induced organic reaction enhancement (MORE) technique. A benign, simple, and versatile route to a Schiff-base ligand and its metal complexes has been explored. Neat reactants were subjected

Parvez Ali; P. Ramakanth; Jyotsna Meshram

2010-01-01

250

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

251

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

2012-10-05

252

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 NH···O hydrogen bond links the flat conjugated HNNCCO 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 CH⋯O hydrogen bonds. The molecules are linked into three dimensional framework structure by a combination of mainly NH⋯N and NH⋯O hydrogen bonds and weak CF⋯? and ?⋯? interactions.

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

2013-10-01

253

Crystal structures of copper(II) chloride, copper(II) bromide, and copper(II) nitrate complexes with pyridine-2-carbaldehyde thiosemicarbazone  

SciTech Connect

The crystal structures of chloro-(2-formylpyridinethiosemicarbazono)copper dimethyl sulfoxide solvate (I), bromo-(2-formylpyridinethiosemicarbazono)copper (II), and (2-formylpyridinethiosemicarbazono)copper(II) nitrate dimethyl sulfoxide solvate (III) are determined using X-ray diffraction. In the crystals, complexes I and II form centrosymmetric dimers in which the thiosemicarbazone sulfur atom serves as a bridge and occupies the fifth coordination site of the copper atom of the neighboring complex related to the initial complex through the center of symmetry. In both cases, the coordination polyhedron of the complexing ion is a distorted tetragonal bipyramid. Complex III in the crystal structure forms polymer chains in which the copper atom of one complex forms the coordination bond with the thicarbamide nitrogen atom of the neighboring complex. In this structure, the coordination polyhedron of the central atom is an elongated tetragonal bipyramid. It is established that complexes I-III at a concentration of 10{sup -5} mol/l selectively inhibit the growth of 60 to 90 percent of the cancer tumor cells of the human myeloid leukemia (HL-60).

Chumakov, Yu. M., E-mail: chumakov.xray@phys.asm.md [Academy of Sciences of Moldova, Institute of Applied Physics (Moldova, Republic of); Tsapkov, V. I. [State University of Moldova (Moldova, Republic of); Jeanneau, E. [Universite Claude Bernard, Laboratoire des Multimateriaux et Interfaces (France); Bairac, N. N. [State University of Moldova (Moldova, Republic of); Bocelli, G. [National Research Council (IMEM-CNR), Institute of Materials for Electronics and Magnetism (Italy); Poirier, D.; Roy, J. [Centre Hospitalier Universitaire de Quebec (CHUQ) (Canada); Gulea, A. P. [State University of Moldova (Moldova, Republic of)

2008-09-15

254

Cytotoxic evaluation of 3-aminopyridine-2-carboxaldehyde thiosemicarbazone in peripheral blood lymphocytes of patients with refractory solid tumors using electron paramagnetic resonance  

PubMed Central

3-Aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP) is a metal chelator that potently inhibits the enzyme ribonucleotide reductase (RR), which plays a key role in cell division and tumor progression. A subunit of RR has a non-heme iron and a tyrosine-free radical, which are required for the enzymatic reduction of ribonucleotides to deoxyribonucleotides. The objective of the present study was to determine whether 3-AP affects its targeted action by measuring electron paramagnetic resonance (EPR) signals formed either directly or indirectly from low molecular weight ferric-3-AP chelates. Peripheral blood lymphocytes were collected from patients with refractory solid tumors at baseline and at 2, 4.5 and 22 h after 3-AP administration. Using EPR spectra, our study identified signals from high-spin Fe-transferrin, high-spin heme and low-spin iron or copper ions. An increase in the Fe-transferrin signal was observed, suggesting blockage of Fe uptake. It is hypothesized that formation of reactive oxygen species by FeT2 or CuT damages the transferrin or the transferrin receptor. An increase in the heme signal was also observed, which was a probable source of cytochrome c release from the mitochondria and potential apoptosis. In addition, increased levels of Fe and Cu were identified. These results, which were consistent with our previous study validating 3-AP-mediated signals by EPR, provide valuable insights into the in vivo mechanism of action of 3-AP.

KOLESAR, JILL M.; SACHIDANANDAM, KAMAKSHI; SCHELMAN, WILLIAM R.; EICKHOFF, JENS; HOLEN, KYLE D.; TRAYNOR, ANNE M.; ALBERTI, DONA B.; THOMAS, JAMES P.; CHITAMBAR, CHRISTOPHER R.; WILDING, GEORGE; ANTHOLINE, WILLIAM E.

2011-01-01

255

PAN-811 (3-aminopyridine-2-carboxaldehyde thiosemicarbazone), a novel neuroprotectant, elicits its function in primary neuronal cultures by up-regulating Bcl-2 expression.  

PubMed

Neurotoxicity in primary neurons was induced using hypoxia/hypoglycemia (H/H), veratridine (10microM), staurosporine (1microM) or glutamate (100microM), which resulted in 72%, 67%, 75% and 66% neuronal injury, respectively. 3-Aminopyridine-2-carboxaldehyde thiosemicarbazone (PAN-811; 10microM; Panacea Pharmaceuticals, Gaithersburg, MD) pretreatment for 24 h provided maximal neuroprotection of 89%, 42%, 47% and 89% against these toxicities, respectively. Glutamate or H/H treatment of cells increased cytosolic cytochrome c levels, which was blocked by pretreatment of cells with PAN-811. Pretreatment of neurons with PAN-811 produced a time-dependent increase in the protein level of Bcl-2, which was evident even after glutamate or H/H treatments. An up-regulation in the expression of the p53 and Bax genes was also observed following exposure to these neurotoxic insults; however, this increase was not suppressed by PAN-811 pretreatment. Functional inhibition of Bcl-2 by HA14-1 reduced the neuroprotective efficacy of PAN-811. PAN-811 treatment also abolished glutamate or H/H-mediated internucleosomal DNA fragmentation. PMID:16084648

Chen, R-W; Yao, C; Lu, X C M; Jiang, Z-G; Whipple, R; Liao, Z; Ghanbari, H A; Almassian, B; Tortella, F C; Dave, J R

2005-01-01

256

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

257

Cytotoxic Evaluation of 3-Aminopyridine-2-Carboxaldehyde Thiosemicarbazone, 3-AP, in Peripheral Blood Lymphocytes of Patients with Refractory Solid Tumors using Electron Paramagnetic Resonance.  

PubMed

PURPOSE: 3-AP (3-aminopyridine-2-carboxaldehyde thiosemicarbazone, 3-AP) is a metal chelator that potently inhibits the enzyme ribonucleotide reductase, RR, which plays a key role in cell division and tumor progression. A sub-unit of RR has a non-heme iron and a tyrosine free radical, which are required for the enzymatic reduction of ribonucleotides to deoxyribonucleotides. The objective of the study was to determine whether 3-AP affects its targeted action by measuring EPR signals formed either directly or indirectly from low molecular weight ferric-3-AP chelates. METHODS: Peripheral blood lymphocytes were collected from patients with refractory solid tumors at baseline and at 2, 4.5 and 22 hours after 3-AP administration. EPR spectra were used to identify signals from high-spin Fe-transferrin, high-spin heme and low-spin iron or copper ions. RESULTS: An increase in Fe-transferrin signal was observed, suggesting blockage of Fe uptake. It is hypothesized that formation of reactive oxygen species by FeT(2) or CuT damage transferrin or the transferrin receptor. An increase in heme signal was also observed, which is a probable source of cytochrome c release from the mitochondria and potential apoptosis. In addition, increased levels of Fe and Cu were identified. CONCLUSION: These results, which were consistent with our earlier study validating 3-AP-mediated signals by EPR, provide valuable insights into the in vivo mechanism of action of 3-AP. PMID:21373381

Kolesar, Jill M; Sachidanandam, Kamakshi; Schelman, William R; Eickhoff, Jens; Holen, Kyle D; Traynor, Anne M; Alberti, Dona B; Thomas, James P; Chitambar, Christopher R; Wilding, George; Antholine, William E

2011-01-01

258

Identification of in vitro metabolites of the novel anti-tumor thiosemicarbazone, DpC, using ultra-high performance liquid chromatography-quadrupole-time-of-flight mass spectrometry.  

PubMed

Di-2-pyridylketone-4-cyclohexyl-4-methyl-3-thiosemicarbazone (DpC) is a promising analogue of the dipyridyl thiosemicarbazone class currently under development as a potential anti-cancer drug. In fact, this class of agents shows markedly greater anti-tumor activity and selectivity than the clinically investigated thiosemicarbazone, Triapine®. However, further development of DpC requires detailed data concerning its metabolism. Therefore, we focused on the identification of principal phase I and II metabolites of DpC in vitro. DpC was incubated with human liver microsomes/S9 fractions and the samples were analyzed using ultra-performance liquid chromatography (UPLC(TM)) with electrospray ionization quadrupole-time-of-flight (Q-TOF) mass spectrometry. An Acquity UPLC BEH C(18) column was implemented with 2 mM ammonium acetate and acetonitrile in gradient mode as the mobile phase. The chemical structures of metabolites were proposed based on the accurate mass measurement of the protonated molecules as well as their main product ions. Ten phase I and two phase II metabolites were detected and structurally described. The metabolism of DpC occurred via oxidation of the thiocarbonyl group, hydroxylation and N-demethylation, as well as the combination of these reactions. Conjugates of DpC and the metabolite, M10, with glucuronic acid were also observed as phase II metabolites. Neither sulfate nor glutathione conjugates were detected. This study provides the first information about the chemical structure of the principal metabolites of DpC, which supports the development of this promising anti-cancer drug and provides vital data for further pharmacokinetic and in vivo metabolism studies. PMID:23180090

Stariat, Ján; Kova?íková, Petra; Ku?era, Radim; Klimeš, Ji?í; Kalinowski, Danuta S; Richardson, Des R; Ketola, Raimo A

2012-11-22

259

Palladium(II) and platinum(II) complexes of pyridine-2-carbaldehyde thiosemicarbazone with potential biological activity. Synthesis, structure and spectral properties. Extended network via hydrogen bond linkages of [Pd(PyTsc)Cl  

Microsoft Academic Search

The reactions of Li2PdCl4 and Na2PtCl4 with pyridine-2-carbaldehyde thiosemicarbazone, HPyTsc, afforded the complexes [Pd(PyTsc)Cl], [Pd(PyTsc)2] and [Pt(PyTsc)Cl], [Pt(PyTsc)2]. The new complexes have been characterized by elemental analyses and spectroscopic studies. A crystal structure of [Pd(PyTsc)Cl] shows that the anion of PyTsc coordinates in a planar conformation to the central palladium(II) through the pyridyl N, azomethine N and thiolato S atoms.

Dimitra Kovala-Demertzi; John R. Miller; Nikolaos Kourkoumelis; Sotiris K. Hadjikakou; Mavroudis A. Demertzis

1999-01-01

260

Synthesis and characterization of new copper thiosemicarbazone complexes with an ONNS quadridentate system: cell growth inhibition, S-phase cell cycle arrest and proapoptotic activities on cisplatin-resistant neuroblastoma cells  

Microsoft Academic Search

Two new copper thiosemicarbazone complexes with an ONNS quadridentate system were synthesized and evaluated for anticancer\\u000a activity on cisplatin-resistant neuroblastoma cells. Among these two copper complexes, the substituted 8-hydroxyquinoline-2-carboxaldehyde–4,4-dimethyl-3-thiosemicarbazide\\u000a (CuHQDMTS) exhibited stronger cell growth inhibition activity than the unsubstituted copper 8-hydroxyquinoline-2-carboxaldehyde\\u000a thiosemicarbazide complex (CuHQTS). Both CuHQTS and CuHQDMTS showed dose-dependent cell growth inhibition, cell cycle arrest\\u000a and apoptosis induction activities

Haiyuan Zhang; Ronald Thomas; David Oupicky; Fangyu Peng

2008-01-01

261

A multicenter phase II trial of 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3AP, Triapine ® ) and gemcitabine in advanced non-small-cell lung cancer with pharmacokinetic evaluation using peripheral blood mononuclear cells  

Microsoft Academic Search

Summary  \\u000a Background: We tested the hypothesis that 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP, Triapine®) may enhance response to\\u000a re-treatment with gemcitabine by enhancing intracellular uptake of gemcitabine in a phase II study. Method: Patients who had prior exposure to gemcitabine as a first-line treatment of advanced non-small-cell lung cancer (NSCLC) were\\u000a given weekly infusions of 3-AP and gemcitabine for 3 weeks followed by 1 week

Brigette Ma; Boon Cher Goh; Eng Huat Tan; Kwok Chi Lam; Ross Soo; Swan Swan Leong; Ling Zhi Wang; Frankie Mo; Anthony T. C. Chan; Benny Zee; Tony Mok

2008-01-01

262

3,5-diacetyl-1,2,4-triazol bis(4N-substituted thiosemicarbazone) palladium(II) complexes: synthesis, structure, antiproliferative activity and low toxicity on normal kidney cells.  

PubMed

Treatment of (4)N-monosubstituted bis(thiosemicarbazone) ligands of 3,5-diacetyl-1,2,4-triazol series with lithium tetrachloridopalladate gave the dinuclear complexes of general formula [Pd(?-H(3)L(1-5))](2), but using dichloridobistriphenylphosphinepalladium(II) salt, the first mononuclear bis(thiosemicarbazone)-palladium-triphenylphosphine complexes of the 3,5-diacetyl-1,2,4-triazol series, [Pd(H(3)L(1-5))PPh(3)], have been obtained. All the compounds have been characterized by elemental analysis and by IR and NMR spectroscopy, and the crystal and molecular structures of dinuclear complexes [Pd(?-H(3)L(3))](2) and [Pd(?-H(3)L(5))](2) as well as mononuclear complexes [Pd(H(3)L(1))PPh(3)], [Pd(H(3)L(2))PPh(3)], [Pd(H(3)L(3))PPh(3)] and [Pd(H(3)L(4))PPh(3)] have been determined by X-ray crystallography. The new compounds synthesized have been evaluated for antiproliferative activity in vitro against NCI-H460, A2780 and A2780cisR human cancer cell lines. Subsequent toxicity study, on normal renal LLC-PK1 cells, shows that all compounds investigated exhibit very low toxicity on kidney cells with respect to cisplatin. PMID:22071086

Matesanz, Ana I; Hernández, Carolina; Rodríguez, Ana; Souza, Pilar

2011-08-28

263

Zinc(II) complexes of 2-acetyl pyridine 1-(4-fluorophenyl)-piperazinyl thiosemicarbazone: Synthesis, spectroscopic study and crystal structures - potential anticancer drugs.  

PubMed

2-Acetyl pyridine thiosemicarbazone containing an 1-(4-fluorophenyl)-piperazinyl ring incorporated at N(4)-position, HAcPipPheF (1) and the zinc(II) complexes [Zn(AcPipPheF)(2)] (2) and [Zn(OAc)(AcPipPheF)](2) (3) have been prepared and structurally characterized by means of vibrational and NMR ((1)H and (13)C) spectroscopy. The crystal structures of the compounds 1-3 have been determined by X-ray crystallography. The metal coordination geometry of [Zn(AcPipPheF)(2)] is described as distorted octahedral configuration in a trans-N-cis-N-cis-S configuration. In [Zn(OAc)(AcPipPheF)](2) one of the acetato group exhibits monoatomic bridge and the other bridges in a bidentate manner. The zinc(1) metal ion is coordinated in a distorted octahedral configuration while the metal coordination of Zn(2) is described as distorted square pyramidal. Biomedical studies revealed that, compounds 1-3 displayed potent anticancer activity. The antiproliferative activity of 1-3 was found to be considerably stronger than that of cis-platin. The IC(50) values range from 26 to 90nM, against all cell lines tested, while for cis-platin the IC(50) values range from 2 to 17microM and for the zinc salt, ZnCl(2), the IC(50) values range from 81 to 93microM. The complex 3 shows the highest activity against all four cancer cell lines and the highest selectivity against K562 and MDA-MB-453 cancer cell lines. The compounds inhibited tumor cell proliferation by arresting the cell cycle progression at the S phase. PMID:20102782

Stanojkovic, Tatjana P; Kovala-Demertzi, Dimitra; Primikyri, Alexandra; Garcia-Santos, Isabel; Castineiras, Alfonso; Juranic, Zorica; Demertzis, Mavroudis A

2010-01-07

264

Copper-64 radiolabelling of the C2A domain of synaptotagmin I using a functionalised bis(thiosemicarbazone): A pre- and post-labelling comparison.  

PubMed

Dysregulation of apoptosis and necrosis is central to many diseases and non-invasive imaging of cell death is an important clinical objective to stage disease or to monitor treatment progress. The C2A domain of rat synaptotagmin I binds to phosphatidylserine (PS) exposed during cell death and modification to its lysine residues has been shown to disrupt PS binding. Site-specifically labelled (99m)Tc(CO)3-C2AcH and (68)Ga-C2Ac have previously been investigated for single photon emission computed tomography (SPECT) and positron emission tomography (PET) imaging, respectively. We wished to design a (64)Cu-labelled counterpart due to the longer half-life of (64)Cu. Since the calcium binding sites in C2A may interfere with copper binding we sought a high affinity, fast labelling chelator. We synthesised a maleimide functionalised bis(thiosemicarbazone), H2ATSE/AMal, for the site-specific copper-64 radiolabelling of thiol-functionalised C2Ac. When radiolabelling was performed by incubation of the ligand-protein conjugate (post-labelling approach), analysis of the resultant (64)CuATSE/AMal-C2Ac revealed that the C2Ac was able to compete for radiocopper with the chelator. In contrast, the pre-labelled (64)CuATSE/AMal-C2Ac conjugate revealed good stability in serum and maintained target affinity in a red blood cell binding assay. The results suggest that due to the intrinsic copper binding properties of the protein, a pre-labelling approach is preferred for the C2Ac domain of synaptotagmin I when copper is the desired radioisotope. PMID:23954480

Hueting, Rebekka; Tavaré, Richard; Dilworth, Jonathan R; Mullen, Gregory E

2013-07-22

265

Synthesis, characterization, and preliminary in vitro studies of vanadium(IV) complexes with a Schiff base and thiosemicarbazones as mixed-ligands  

PubMed Central

[VO(Sal-L-tryp)(H2O)] 1 (where sal-L-tryp = N-salicylidene-L-tryptophanate) was used as a precursor to produce the novel complexes, [VO(Sal-L-tryp)(MeATSC)].1.5C2H5OH 2 (where MeATSC = 9-Anthraldehyde-N(4)-methylthiosemicarbazone), [VO(Sal-L-tryp)(N-Ethhymethohcarbthio)].H2O 3 (where N-Ethhymethohcarbthio = (E)-N-ethyl-2-(4-hydroxy-3-methoxybenzylidene)hydrazinecarbothioamide), and [VO(Sal-L-tryp)(acetylethTSC)].C2H5OH 4 (where acetylethTSC = (E)-N-ethyl-2-(1-(thiazol-2-yl)ethylidene)hydrazinecarbothioamide), by reaction with the respective thiosemicarbazone. The chemical and structural properties of these ligands and complexes were characterised by elemental analysis, ESI MS, FT-IR, UV-visible, ESR, 1H and 13C NMR spectroscopy, and X-ray crystallography. DMSO and DMSO-d6 solutions of compounds 1-4 were oxidised in air to produce vanadium(V) species which were verified by ESI MS and 51V NMR spectroscopy. Anti-cancer properties of compounds 2-4 were examined with three colon cancer cell lines, HTC-116, Caco-2, and HT-29, and also with non-cancerous colonic myofibroblasts, CCD18-Co. Compounds 2-3 exhibited less inhibitory effects in the CCD-18Co cells, indicating a possible cytotoxic selectivity towards colon cancer cells. In general, those compounds which exhibited anti-proliferative activity on cancer cells, but did not affect non-cancerous cells, may have a potential in chemotherapy.

Lewis, Nerissa A.; Liu, Fange; Seymour, Luke; Magnusen, Anthony; Erves, Travis R.; Arca, Jessa Faye; Beckford, Floyd A.; Venkatraman, Ramaiyer; Gonzalez-Sarrias, Antonio; Fronczek, Frank R.; VanDerveer, Don G.; Seeram, Navindra P.; Liu, Aimin; Jarrett, William L.; Holder, Alvin A.

2013-01-01

266

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

2011-11-03

267

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

268

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

2008-02-16

269

A Phase II study of 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP) and gemcitabine in advanced pancreatic carcinoma. A trial of the Princess Margaret hospital Phase II consortium.  

PubMed

3-Aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP, Triapine, Vion Pharmaceuticals, New Haven, CT) is an inhibitor of the M2 subunit of ribonucleotide reductase (RR). Preclinical testing demonstrates synergy between 3-AP and gemcitabine. Phase I studies of the combination have suggested tolerability and some initial evidence of efficacy. Therefore, a phase II study of gemcitabine plus 3-AP in advanced pancreatic carcinoma was undertaken. In this two-step phase II trial, patients with advanced pancreatic adenocarcinoma who had not received prior chemotherapy for advanced disease were treated with 3-AP 105 mg/m(2) given over 2 h. Four hours after the 3-AP infusion was completed, gemcitabine 1,000 mg/m(2) was given over 30 min. Both drugs were given on days 1, 8 and 15 of a 28-day cycle.Twenty-six patients were enrolled to the study. One patient withdrew consent prior to receiving any treatment and is excluded from all further analyses. Four patients discontinued treatment due to adverse effects. Grade 3/4 hematological adverse events included neutropenia, thrombocytopenia, lymphopenia, leukopenia and anemia and the most frequent non-hematological adverse events were fatigue and pain. No objective responses were observed. Eleven patients had stable disease (SD). In five of these eleven patients, SD lasted for more than 6 months. The median time to progression was 4.1 months and the 6 month progression-free survival rate was 29%. The median survival was 9.0 months with a 1-year survival of 28.0%. The combination of 3-AP and gemcitabine is associated with moderate toxicity in patients with advanced pancreatic cancer. This two-stage trial was stopped after stage I due to lack of antitumour activity. On the basis of this clinical trial, the combination of gemcitabine and 3-AP at this dose and schedule does not warrant further study in this patient population. PMID:17585372

Mackenzie, M J; Saltman, D; Hirte, H; Low, J; Johnson, C; Pond, G; Moore, M J

2007-06-22

270

New palladium and platinum complexes with bioactive 3,5-diacetyl-1,2,4-triazol bis(4-cyclohexyl thiosemicarbazone) ligand: chemistry, antiproliferative activity and preliminary toxicity studies.  

PubMed

The preparation and characterization of the new 3,5-diacetyl-1,2,4-triazol bis(4-cyclohexyl thiosemicarbazone) ligand, H(5)L(1), is described. Treatment of H(5)L(1) with K(2)PtCl(4) gave the dinuclear complex [Pt(H(3)L(1))](2), 1, but using MCl(2)(PPh(3))(2) where M = Pd or Pt, mononuclear complexes 2 and 3, of general formula [M(H(3)L(1))PPh(3)], were obtained. Subsequent reaction of the [Pd(H(3)L(1))PPh(3)] complex with PdCl(2)(PPh(3))(2) yielded a new dinuclear complex [(PPh(3))Pd(H(2)L(1))PdCl], 4. All compounds have been characterized by elemental analysis and FAB(+) spectrometry and by IR and NMR spectroscopy. The molecular structures of mononuclear complexes 2 and 3 and dinuclear complex 4 have been determined by X-ray crystallography. The new compounds synthesized have been evaluated for antiproliferative activity in vitro against NCI-H460, HepG2, MCF-7, A2780 and A2780cisR human cancer cell lines. The cytotoxicity data suggest that the H(5)L(1) ligand and [Pt(H(3)L(1))](2), complex 1, may be endowed with important cytotoxic properties since they are capable of not only circumventing cisplatin resistance in A2780cisR but also exhibit antiproliferative activity in NCI-H460. The interactions of these compounds with calf thymus DNA were investigated by UV-vis absorption and a nephrotoxic study, in LLC-PK1 cells, has also been carried out. PMID:22955178

Matesanz, Ana I; Perles, Josefina; Souza, Pilar

2012-10-28

271

Synthesis of some new pyrimidine and fused pyrimidine derivatives (Part 2).  

PubMed

6-Oxo-4(2-thienyl)-2-thioxo-1,3-dihydropyrimidine-5-carbonitrile (1) was synthesized and reacted with alkyl halides to give the S-alkyl compounds (2a,b), which reacted with phosphorous oxychloride to yield (3a,b). Reaction of 3a,b with phenyl-hydrazine, hydrazine hydrate, ammonia, acid hydrazides and thiourea leads to formation of the compounds (4a,b), the dihydrazino compound derivative (5), the amino compounds (7a,b), triazolopyrimidine derivatives (9a-d), and the mercapto compounds (10a,b), respectively. Treatment of (10a) with chloroacetone gave (11a), which condensed with benzaldehyde giving the tricyclic compound (12). Also (10b) reacted with ethyl chloroacetate followed by hydrolysis and cyclization yielded (14). Heating of (5) gave (6), which reacted with sodium nitrite and/or carbondisulphide and give (15) and (16), respectively. PMID:12806830

Ahmed, Gamal A; el-Salam, Nasser M

2003-04-01

272

Bis(ethanol-?O)bis-(pyridine-3-carb-aldehyde-?N thio-semicarbazone)bis-(thio-cyanato-?N)iron(II)-pyridine-3-carbaldehyde thio-semicarbazone (1/2)  

PubMed Central

The crystal structure of the title FeII complex, [Fe(NCS)2(C7H8N4S)2(CH3CH2OH)2]·2C7H8N4S, based on the Schiff base ligand pyridine-3-carbaldehyde thio­semicarbazone (pct), results from the cocrystallization of an FeII coordination compound together with two of the pct ligands. The complex unit is mononuclear, with the central FeII ion located on a crystallographic centre of inversion and coordinated by four N atoms from two pct ligands and two thio­cyanate anions. The slightly distorted octa­hedral coordination is completed by two O atoms from ethanol mol­ecules. The crystal packing is accomplished inter­molecular N—H?S hydrogen bonds.

Wang, Shao-Mei

2009-01-01

273

Mixed ligand palladium(II) complexes of 6-methoxy-2-oxo-1,2-dihydroquinoline-3-carbaldehyde 4N-substituted thiosemicarbazones with triphenylphosphine co-ligand: synthesis, crystal structure and biological properties.  

PubMed

A series of new 6-methoxy-2-oxo-1,2-dihydroquinoline-3-carbaldehyde 4N-substituted thiosemicarbazone ligands (H2L1–H2L5) and their corresponding palladium(II) complexes [Pd(L1)(PPh3)] (1), [Pd(L2)(PPh3)] (2), [Pd(HL3)(PPh3)]Cl (3), [Pd(L4)(PPh3)] (4) and [Pd(L5)(PPh3)] (5), have been synthesized in order to evaluate the effect of terminal N-substitution in thiosemicarbazone moiety on coordination behaviour and biological activity. The new ligands and their corresponding complexes were characterized by analytical and various spectral techniques. The molecular structure of the complexes 2–5 were characterized by single crystal X-ray diffraction studies which revealed that the ligands H2L2, H2L4 and H2L5 are coordinated to palladium(II) as binegative tridentate (ONS2?) by forming six and five member rings whereas, the ligand H2L3 coordinated to Pd(II) as uninegative tridentate (ONS?). The interactions of the new complexes with calf thymus DNA (CT-DNA) have been evaluated by absorption and ethidium bromide (EB) competitive studies which revealed that complexes 1–5 could interact with CT-DNA through intercalation. Further, the interactions of the complexes with bovine serum albumin (BSA) were also investigated using UV-visible, fluorescence and synchronous fluorescence spectroscopic methods, which showed that the new complexes could bind strongly with BSA. Antioxidant studies showed that all the complexes have a strong antioxidant activity against 2-2?-diphenyl-1-picrylhydrazyl (DPPH) radical and 2,2?-azino-3-ethylbenzthiazoline-6-sulfonic acid diammonium salt (ABTS) cation radical. In addition, in vitro cytotoxicity of the complexes against human lung cancer (A549) cell line was assayed which showed that 4 has higher cytotoxic activity than the rest of the complexes and cisplatin. PMID:22864662

Ramachandran, Eswaran; Senthil Raja, Duraisamy; Bhuvanesh, Nattamai S P; Natarajan, Karuppannan

2012-11-21

274

Synthesis and Characterization of Novel Thiosemicarbazones Bearing Sugar Moieties 1 1 Supported by the Program for New Century Excellent Talents in University (No. NCET-04–04649), the National Natural Science Foundation of China (No 20475030), and the Start-up Fund for Doctoral Scientific Research of Qingdao University of Science and Technology  

Microsoft Academic Search

Six novel thiosemicarbazones containing sugar and thiosemicarbazide moieties were synthesized by a five-step procedure using D-galactose and D-xylose as the starting materials and the corresponding glycosyl isothiocyanates as the intermediates. The target compounds were characterized by IR, 1H NMR, and elemental analysis. The coupling constants between H1 and H2 in the sugar rings, all fall within the range of J

Bo YANG; Shu-sheng ZHANG; Hui-xiang LI

2006-01-01

275

Betulinol derivatives  

US Patent & Trademark Office Database

The present invention is directed to betulinol derivatives and betulinol-antibody conjugates having the formulae: ##STR1## and and, in particular, betulinol dimethyl ether. Methods for making and using these derivatives and conjugates, as well as a method for making and using betulonic aldehyde, are also disclosed.

Bomshteyn; Arkadiy L. (Brooklyn, NY); Rathnam; Premila (Englewood Cliffs, NJ); Saxena; Brij B. (Englewood, NJ)

2005-05-10

276

Determination of absolute photoionization cross-sections of aromatics and aromatic derivatives.  

PubMed

The absolute photoionization cross-sections of aromatics and aromatic derivatives including toluene, ethylbenzene, n-propylbenzene, o-xylene, m-xylene, p-xylene, 1,3,5-trimethylbenzene, styrene, phenylacetylene, indene, indane, 1-methylnaphthalene, benzyl alcohol and benzaldehyde were measured at the photon energy range from ionization thresholds to 11.7 eV. The experiments were performed by tunable synchrotron vacuum ultraviolet (VUV) photoionization mass spectrometry. Benzene was chosen as a calibration standard, since its photoionization cross-section is well known. Binary liquid mixtures of the investigated molecules and benzene were used in the measurements. Photo-induced fragments from the molecules were also observed, and their photoionization cross-sections are also presented. PMID:19918935

Zhou, Zhongyue; Xie, Mingfeng; Wang, Zhandong; Qi, Fei

2009-12-01

277

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 Central

In the title 1:1 co-crystal, [PtCl2(C11H14ClN3O)2]·C7H5ClO, the coordination polyhedron of the PtII atom is slightly distorted square-planar with the chloride and 2,3-di­hydro-1,2,4-oxa­diazole ligands mutually trans, as the Pt atom lies on an inversion center. The 4-chloro­benzaldehyde mol­ecules are statistically disordered about an inversion centre with equal occupancies for the two positions. The PtII complex forms a three-dimensional structure through C—H?Cl and weaker C—H?O inter­actions with the 4-chloro­benzaldehyde mol­ecule.

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

2013-01-01

278

Complex derivatives  

NASA Astrophysics Data System (ADS)

The intrinsic complexity of the financial derivatives market has emerged as both an incentive to engage in it, and a key source of its inherent instability. Regulators now faced with the challenge of taming this beast may find inspiration in the budding science of complex systems.

Battiston, Stefano; Caldarelli, Guido; Georg, Co-Pierre; May, Robert; Stiglitz, Joseph

2013-03-01

279

IR spectra of protonated benzaldehyde clusters, C7H7O+-Ln (L=Ar,N2n<=2): Ion-ligand binding motifs of the cis and trans oxonium isomers  

NASA Astrophysics Data System (ADS)

Infrared photodissociation (IRPD) spectra of mass-selected protonated benzaldehyde (C7H7O+,BZH+) and its weakly bound clusters with Ar and N2 produced in an electron impact source are recorded in the C-H and O-H stretch ranges. The experimental results are supported by ab initio and density functional calculations. Analysis of the IRPD spectrum of the BZH+ monomer is consistent with the presence of the cis and trans isomers of the oxonium ions, which is confirmed by the cluster spectra. No signature of the less stable carbenium ions is detected. Frequency shifts in the IRPD spectra of dimers and trimers provide information about the preferred intermolecular ligand binding site (?-bonding versus H-bonding) and the corresponding interaction strength. H-bonding to the OH group of the oxonium ions of BZH+ is found to be favored over ?-bonding to the aromatic ring for both Ar and N2. There are significant differences in the microsolvation structure and energetics of the cis and trans oxonium isomers of BZH+ due to the rather different acidities of their OH groups and isomer-dependent effects arising from steric hindrance. The large positive partial charge of the protonated formyl group implies that the cluster growth of the larger clusters continues by further solvation of the protonated substituent rather than the aromatic ring.

Chakraborty, Shamik; Patzer, Alexander; Dopfer, Otto

2010-07-01

280

Influence of Formazan Derivatives on Corrosion Inhibition of Mild Steel in Hydrochloric Acid Medium  

Microsoft Academic Search

Formazan of benzaldehyde (FB) and formazan of p-dimethyl amino benzaldehyde (FD) were synthesized. These compounds were studied as corrosion inhibitor for mild steel in 1.11 N hydrochloric acid by weight loss method. The result showed that the corrosion inhibition efficiency of these compounds was found to vary with the temperature and acid concentration. Also, it was found that the corrosion

P. VENKATESAN; B. ANAND; P. MATHESWARAN

281

Glycal Derivatives  

NASA Astrophysics Data System (ADS)

Glycals are unsaturated sugar derivatives in which the double bond engages the anomeric carbon atom. Such cyclic vinyl ethers are characterized by high reactivity, allowing for regio- and stereoselective transformations, directly or indirectly related to glycosylation, as well as to formation of carbon-carbon and carbon-heteroatom bonds at the anomeric center. This review provides a systematic survey of chemical synthetic methods, by which the carbon-carbon double bond is introduced next to the ring oxygen, in an endo- or exocyclic position. Some mechanistic aspects are discussed in relation to traditional methods of glycal preparation, which rely on elimination reactions. Glycal-to-glycal rearrangement and applications of organometallic chemistry and heteroatom-induced transformations for syntheses and activation of glycals are also highlighted.

Priebe, Waldemar; Fokt, Izabela; Grynkiewicz, Grzegorz

282

N(4)-Tolyl-2-acetylpyridine thiosemicarbazones and their platinum(II,IV) and gold(III) complexes: cytotoxicity against human glioma cells and studies on the mode of action.  

PubMed

Complexes [Au(2Ac4oT)Cl][AuCl2] (1), [Au(Hpy2Ac4mT)Cl2]Cl·H2O (2), [Au(Hpy2Ac4pT)Cl2]Cl (3), [Pt(H2Ac4oT)Cl]Cl (4), [Pt(2Ac4mT)Cl]·H2O (5), [Pt(2Ac4pT)Cl] (6) and [Pt(L)Cl2OH], L = 2Ac4mT (7), 2Ac4oT (8), 2Ac4pT (9) were prepared with N(4)-ortho- (H2Ac4oT), N(4)-meta- (H2Ac4mT) and N(4)-para- (H2Ac4pT) tolyl-2-acetylpyridine thiosemicarbazone. The cytotoxic activities of all compounds were assayed against U-87 and T-98 human malignant glioma cell lines. Upon coordination cytotoxicity improved in 2, 5 and 8. In general, the gold(III) complexes were more cytotoxic than those with platinum(II,IV). Several of these compounds proved to be more active than cisplatin and auranofin used as controls. The gold(III) complexes probably act by inhibiting the activity of thioredoxin reductase enzyme whereas the mode of action of the platinum(II,IV) complexes involves binding to DNA. Cells treated with the studied compounds presented morphological changes such as cell shrinkage and blebs formation, which indicate cell death by apoptosis induction. PMID:23749148

Ferraz, Karina S O; Da Silva, Jeferson G; Costa, Flávia M; Mendes, Bruno M; Rodrigues, Bernardo L; Dos Santos, Raquel G; Beraldo, Heloisa

2013-06-09

283

Some polyhydroxy azo azomethine derivatives of salicylaldehyde: Synthesis, characterization, spectroscopic, molecular structure and antimicrobial activity studies  

NASA Astrophysics Data System (ADS)

Some new substituted polyhydroxy azo azomethine compounds were prepared by reaction of tris(hydroxymethyl)aminomethane with (E)-2-hydroxy-5-(phenyldiazenyl) benzaldehyde and its substituted derivatives. The structures of azo and azo azomethine compounds were determined by IR, UV vis, 1H NMR and 13C NMR spectroscopic techniques, and/or X-ray diffraction studies. According to IR spectra, all azo azomethine compounds adopt keto form in solid state. UV vis analysis has shown the presence of keto enol tautomerism in solution for all azo azomethine compounds, except that for nitro substituted derivative, enol form is dominantly favored in solution. At the same time, above mentioned derivative compounds were studied in vitro for their antimicrobial properties. Among the phenylazosalicylaldehyde series compound tested, 4-phenylazosalicylaldehyde, 4-(3-chlorophenylazo)salicylaldehyde, 4-(2-chlorophenylazo)salicylaldehyde, 4-(4-fluorophenylazo)salicylaldehyde, 4-(3-chlorophenylazo)salicylaldehyde and 4-(4-ethylphenylazo)salicylaldehyde showed a weak antimicrobial activity only against gram positive bacteria. On the contrary, phenylazosalicylaldehyde series compounds were reacted tris(hydroxmethyl)aminomethane, that exhibited a strong antimicrobial activity against gram positive bacteria, yeast and mould. Moreover, while the 2-{[1,3-dihydroxy-2-(hydroxymethyl)propan-2-ylimino]methyl}phenol did not show an inhibition on tested microorganism, the addition of phenyldiazine groups to 2-{[1,3-dihydroxy-2-(hydroxymethyl)propan-2-ylimino]methyl}phenol resulted in a strong increases in antimicrobial activity.

Odaba?o?lu, Mustafa; Albayrak, Çi?dem; Özkanca, Re?it; Aykan, Fatma Zehra; Lonecke, Peter

2007-09-01

284

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

2012-01-09

285

The Volatile Profiles of a Rare Apple (Malus domestica Borkh.) Honey: Shikimic Acid-Pathway Derivatives, Terpenes, and Others.  

PubMed

The volatile profiles of rare Malus domestica Borkh. honey were investigated for the first time. Two representative samples from Poland (sample?I) and Spain (sample?II) were selected by pollen analysis (44-45% of Malus spp. pollen) and investigated by GC/FID/MS after headspace solid-phase microextraction (HS-SPME) and ultrasonic solvent extraction (USE). The apple honey is characterized by high percentage of shikimic acid-pathway derivatives, as well as terpenes, norisoprenoids, and some other compounds such as coumaran and methyl 1H-indole-3-acetate. The main compounds of the honey headspace were (sample?I; sample?II): benzaldehyde (9.4%; 32.1%), benzyl alcohol (0.3%; 14.4%), hotrienol (26.0%, 6.2%), and lilac aldehyde isomers (26.3%; 1.7%), but only Spanish sample contained car-2-en-4-one (10.2%). CH2 Cl2 and pentane/Et2 O 1?:?2 (v/v) were used for USE. The most relevant compounds identified in the extracts were: benzaldehyde (0.9-3.9%), benzoic acid (2.0-11.2%), terpendiol I (0.3-7.4%), coumaran (0.0-2.8%), 2-phenylacetic acid (2.0-26.4%), methyl syringate (3.9-13.1%), vomifoliol (5.0-31.8%), and methyl 1H-indole-3-acetate (1.9-10.2%). Apple honey contained also benzyl alcohol, 2-phenylethanol, (E)-cinnamaldehyde, (E)-cinnamyl alcohol, eugenol, vanillin, and linalool that have been found previously in apple flowers, thus disclosing similarity of both volatile profiles. PMID:24078598

Ku?, Piotr Marek; Jerkovi?, Igor; Tuberoso, Carlo Ignazio Giovanni; Saroli?, Mladenka

2013-09-01

286

Microwave-induced synthesis and anti-microbial activities of 7,10,11,12-tetrahydrobenzo[c]acridin-8(9H)-one derivatives.  

PubMed

Some new substituted tetrahydroacridin-8-ones and diverse derivatives were synthesized by uncatalysed multi-component reaction of dimedone or cyclohexan-1,3-dione, alpha-naphthylamine and various (o,p,m)-substituted benzaldehydes. The in vitro anti-microbial activities of the prepared compounds were evaluated against some bacteria and fungi strains. The results suggested that, the products 2a-g and 4a-g exhibited good inhibitory effect against most of the tested organisms. Especially, 2f, 2g, 4f and 4g were shown to be most effective against Rhodotorula rubra and Aspergillus parasiticus and compounds 2a, 2c, 2g, 4f and 4g proved to be effective with MIC values in the range of 3.9-7.8 microg/ml. PMID:18718695

Nadaraj, Vetrivel; Selvi, Senniappan Thamarai; Mohan, Sellappan

2008-07-12

287

A phase I and pharmacokinetic study of oral 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP, NSC #663249) in the treatment of advanced stage solid cancers - A California Cancer Consortium Study  

PubMed Central

Background 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3-AP) is a novel small molecule ribonucleotide reductase inhibitor. This study was designed to estimate the maximum-tolerated dose (MTD) and oral bioavailability of 3-AP in patients with advanced stage solid tumors. Methods Twenty patients received one dose of intravenous and subsequent cycles of oral 3-AP following a 3+3 patient dose-escalation. Intravenous 3-AP was administered to every patient at a fixed dose of 100 mg over a 2-hour infusion 1 week prior to the first oral cycle. Oral 3-AP was administered every 12 hours for 5 consecutive doses on days 1–3, days 8–10, and days 15–17 of every 28-day cycle. 3-AP was started at 50 mg with a planned dose escalation to 100, 150, and 200 mg. Dose-limiting toxicities (DLT) and bioavailability were evaluated. Results Twenty patients were enrolled. For dose level 1 (50mg), the second of three treated patients had a DLT of grade 3 hypertension. In the dose level 1 expansion cohort, three patients had no DLTs. No further DLTs were encountered during escalation until the 200 mg dose was reached. At the 200 mg 3-AP dose level, two treated patients had DLTs of grade 3 hypoxia. One additional DLT of grade 4 febrile neutropenia was subsequently observed at the de-escalated 150 mg dose. One DLT in 6 evaluable patients established the MTD as 150 mg per dose on this dosing schedule. Responses in the form of stable disease occurred in 5 (25%) of 20 patients. The oral bioavailability of 3-AP was 67 ± 29%, and was consistent with the finding that the MTD by the oral route was 33% higher than by the intravenous route. Conclusions Oral 3-AP is well-tolerated and has an MTD similar to its intravenous form after accounting for the oral bioavailability. Oral 3-AP is associated with a modest clinical benefit rate of 25% in our treated patient population with advanced solid tumors.

Chao, Joseph; Synold, Timothy W.; Morgan, Robert J.; Kunos, Charles; Longmate, Jeff; Lenz, Heinz-Josef; Lim, Dean; Shibata, Stephen; Chung, Vincent; Stoller, Ronald G.; Belani, Chandra P.; Gandara, David R.; McNamara, Mark; Gitlitz, Barbara J.; Lau, Derick H.; Ramalingam, Suresh S.; Davies, Angela; Espinoza-Delgado, Igor; Newman, Edward M.; Yen, Yun

2012-01-01

288

Syntheses and antitumor activities of potent inhibitors of ribonucleotide reductase: 3-amino-4-methylpyridine-2-carboxaldehyde-thiosemicarba-zone (3-AMP), 3-amino-pyridine-2-carboxaldehyde-thiosemicarbazone (3-AP) and its water-soluble prodrugs.  

PubMed

The reductive conversion of ribonucleotides to deoxyribonucleotides by ribonucleotide reductase (RR) is a crucial and rate-controlling step in the pathway leading to the biosynthesis of DNA, since deoxyribonucleotides are present in extremely low levels in mammalian cells. Mammalian ribonucleotide reductase (RR) is composed of two dissimilar proteins, often referred to as R(1), which contains polythiols and R(2), which contains non-heme iron and a free tyrosyl radical. Both the R(1) and R(2) subunits contribute to the active site of the enzyme. Currently, there are two broad classes of RR inhibitors. The first class includes nucleoside analogs which bind to the R1 subunit of the enzyme, several of which are in development. Among those, Gemcitabine and MDL 101,731 have demonstrated impressive efficacy against various solid tumors. Gemcitabine has now been approved for the treatment of pancreatic cancer and non-small cell lung cancer. The most promising second class of inhibitors of RR includes HCTs [alpha--(N)-heterocyclic carboxaldehyde thiosemicarbazones, e.g., 3-AP and 3-AMP], which exert enzyme inhibitory effect through high affinity binding with non-heme iron. Based on the clinical success achieved by Gemcitabine, it seems reasonable that a strong inhibitor of RR, which is essential for cellular replication, would be a useful addition to the existing therapeutic agents against cancer. In this chapter, we wish to report several highly efficient syntheses for both 3-AP and 3-AMP based upon palladium mediated Stille/Suzuki/Heck coupling reactions. Based upon the in vivo efficacy profile observed with these two agents, 3-AP was chosen over 3-AMP as the candidate for further optimization with the intention to improve its biological and pharmaceutical properties. In this vein, we have completed the synthesis of two water soluble phosphate containing prodrugs and one disulfide-linked prodrug of 3-AP. As expected, bioconversion study using either alkaline phosphatase or glutathione showed that these prodrugs were indeed converted to the parent 3-AP. When evaluated against the murine M-109 lung carcinoma as well as the B16-F10 murine melanoma xenograft models, the newly prepared phosphate prodrugs displayed improved efficacy and safety profiles than that found with the parent. More significantly, the ortho-phosphate prodrug 21 demonstrated impressive antitumor effect using once-a-day dosing regimen. In summary, the results disclosed herein demonstrated that some of 3-AP prodrugs prepared indeed demonstrated improved pharmaceutical, biological and toxicity profiles over the parent 3-AP. Efforts directed towards further optimization of 3-AP prodrugs as novel anticancer agents is clearly warranted. PMID:11172670

Li, J; Zheng, L M; King, I; Doyle, T W; Chen, S H

2001-02-01

289

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

2012-12-09

290

Synthesis, Characterization, Theoretical Crystal Structure, and Antibacterial Activities of Some Transition Metal Complexes of the Thiosemicarbazone (Z)-2-(pyrrolidin-2-ylidene)hydrazinecarbothioamide  

PubMed Central

Problem Statement. In Iraq like most third world countries, attempts discovered new antibiotic drugs derived from thiosemicarbazide and its metal complexes and developed the branch of applied in organic chemistry. Approach. New (Z)-2-(pyrrolidin-2-ylidene)hydrazinecarbothioamide (L) was synthesized in a good yield by the reaction of pyrrolidone with thiosemicarbazide. Co(II), Ni(II), and Cu(II) complexes of (L) were prepared and characterized by FT-IR, UV/visible spectra, 1HNMR, and CHN analyses. Moreover, charge, bond length, bond angle, twist angle, heat of formation, and steric energy were calculated by using of the ChemOffice program, and the DFT calculations for the complexes were done. The free ligand and its metal complexes were tested in vitro against several microorganisms (Staphylococcus aurous, E. coli, Proteus vulgaris, Pseudomonas, and Klebsiella pneumoniae) to assess their antimicrobial properties. Results. The study shows that these complexes have octahedral geometry; in addition, it has high activity against tested bacteria. Conclusion/Recommendations. Based on the reported results, it may be concluded that ligand acts as bidentate, neutral ligand, coordinating through one of the nitrogen and sulfur atoms.

Al-Amiery, Ahmed A.; Al-Majedy, Yasmien K.; Abdulreazak, Haziem; Abood, Hussain

2011-01-01

291

Weather Derivative Valuation  

NASA Astrophysics Data System (ADS)

Weather Derivative Valuation is the first book to cover all the meteorological, statistical, financial and mathematical issues that arise in the pricing and risk management of weather derivatives. There are chapters on meteorological data and data cleaning, the modelling and pricing of single weather derivatives, the modelling and valuation of portfolios, the use of weather and seasonal forecasts in the pricing of weather derivatives, arbitrage pricing for weather derivatives, risk management, and the modelling of temperature, wind and precipitation. Specific issues covered in detail include the analysis of uncertainty in weather derivative pricing, time-series modelling of daily temperatures, the creation and use of probabilistic meteorological forecasts and the derivation of the weather derivative version of the Black-Scholes equation of mathematical finance. Written by consultants who work within the weather derivative industry, this book is packed with practical information and theoretical insight into the world of weather derivative pricing.

Jewson, Stephen; Brix, Anders

2005-04-01

292

Neuroprotective Ganglioside Derivatives.  

National Technical Information Service (NTIS)

In this study, neuroprotective ganglioside derivatives are studied in an attempt to devise neuroprotective agents targeted to specific points in cell death pathways. GMl ganglioside and several of its chemically modified derivatives are neuroprotective in...

M. D. Ullman

2004-01-01

293

Design, Synthesis, and Trypanocidal Activity of New Aminoadamantane Derivatives  

PubMed Central

To develop functionalized adamantanes for treating African trypanosomiasis, we report on the synthesis of new 1-alkyl-2-aminoadamantanes 1a-i, 1-alkyltricyclo[3.3.1.13,7]decan-2-guanylhydrazones 2a-g, and their congeneric thiosemicarbazones 3a,b. The potency of these compounds against Trypanosoma brucei was compared to that of amantadine and rimantadine and found to be substantially higher. The most active analogues, 1c, 1d, 2c, 2g, and 3b, illustrate the synergistic effect of the lipophilic character of the C1 side chain and the C2 functionality on trypanocidal activity.

Papanastasiou, Ioannis; Tsotinis, Andrew; Kolocouris, Nicolas; Prathalingam, S. Radhika; Kelly, John M.

2008-01-01

294

A Rapid, Simple, and Sensitive Spectrophotometric Determination of Traces of Vanadium (V) in Foodstuffs, Alloy Steels, and Pharmaceutical, Water, Soil, and Urine Samples  

Microsoft Academic Search

A rapid, simple, sensitive, and selective spectrophotometric method is investigated for the determination of traces of vanadium (V) in foodstuffs, alloy steels, and pharmaceutical, water, soil, and urine samples in aqueous DMF medium. The metal ion forms a green colored complex with 2-hydroxy-3-methoxy benzaldehyde thiosemicarbazone (HMBATSC) in an acidic buffer of pH 6.0. The green colored solution, having an absorbance

Avvaru Praveen Kumar; Papammagari Raveendra Reddy; Vanka Krishna Reddy

2008-01-01

295

Mesomorphic Derivatives Of Ferrocene  

Microsoft Academic Search

The first series of ferrocene derivatives exhibiting mesomorphic properties (substituted N-(p-benzoyloxybenzylidene) anilines la and 1b) has been synthesized for application in Mössbauer spectroscopy.

Jacques Malthete; Jean Billard

1976-01-01

296

PAN-811 inhibits oxidative stress-induced cell death of human Alzheimer's disease-derived and age-matched olfactory neuroepithelial cells via suppression of intracellular reactive oxygen species.  

PubMed

Oxidative stress plays a significant role in neurotoxicity associated with a variety of neurodegenerative diseases including Alzheimer's disease (AD). Increased oxidative stress has been shown to be a prominent and early feature of vulnerable neurons in AD. Olfactory neuroepithelial cells are affected at an early stage. Exposure to oxidative stress induces the accumulation of intracellular reactive oxygen species (ROS), which in turn causes cell damage in the form of protein, lipid, and DNA oxidations. Elevated ROS levels are also associated with increased deposition of amyloid-beta and formation of senile plaques, a hallmark of the AD brain. If enhanced ROS exceeds the basal level of cellular protective mechanisms, oxidative damage and cell death will result. Therefore, substances that can reduce oxidative stress are sought as potential drug candidates for treatment or preventative therapy of neurodegenerative diseases such as AD. PAN-811, also known as 3-aminopyridine-2-carboxaldehyde thiosemicarbazone or Triapine, is a small lipophilic compound that is currently being investigated in several Phase II clinical trials for cancer therapy due to its inhibition of ribonucleotide reductase activity. Here we show PAN-811 to be effective in preventing or reducing ROS accumulation and the resulting oxidative damages in both AD-derived and age-matched olfactory neuroepithelial cells. PMID:19433896

Nelson, Valery M; Dancik, Chantée M; Pan, Weiying; Jiang, Zhi-Gang; Lebowitz, Michael S; Ghanbari, Hossein A

2009-01-01

297

Irregularities in Imperfective Derivation  

ERIC Educational Resources Information Center

|This article discusses presentation of Russian conjugation via the one-stem system advocated by Lipson and Townsend, and attempts a more unified and complete presentation of irregularities in imperfect derivation. Two major irregularities are occurrence of an unexpected suffix and unpredictable alternation in the root of the derived imperfective.…

Levin, Maurice I.

1977-01-01

298

Higher Derivative Gravity.  

National Technical Information Service (NTIS)

A possible classical route conducting towards a general relativity theory with higher-derivatives starting, in a sense, from first principles, is analysed. A completely causal vacuum solution with the symmetries of the Goedel universe is obtained in the f...

A. J. Accioly

1987-01-01

299

Ferrocene and Ferrocene Derivatives.  

National Technical Information Service (NTIS)

This is an annotated bibliography covering ferrocene and its derivatives from 1962 to August 1966. Several review articles are listed which describe the unique characteristics of ferrocene since its discovery in 1951, its reactions, and some of its uses. ...

W. P. McNutt C. U. Pittman

1966-01-01

300

Neuroprotective Ganglioside Derivatives.  

National Technical Information Service (NTIS)

In this study, neuroprotective ganglioside derivatives are examined so they can be targeted to specific points in cell death pathways. Here, ganglioside functional groups required for neuroprotection and blood-brain barrier permeance are determined. Cell ...

M. D. Ullman

2003-01-01

301

Deriving Common Model Characteristics  

NSDL National Science Digital Library

In this activity, students confront several different models - from the DNA helix Watson and Crick constructed in their laboratory to a map of McDonalds density in the US - and work in small groups to derive their commonalities.

Momsen, Jennifer; Long, Tammy M.; Speth, Elena B.

302

Combinatorics of Partial Derivatives  

Microsoft Academic Search

The natural forms of the Leibniz rule for the kth derivative of a product and of Fa a di Bruno's formula for the kth derivative of a composition involve the dif- ferential operator @k=@x1 @xk rather than dk=dxk, with no assumptions about whether the variables x1;:::;xk are all distinct, or all identical, or partitioned into several distinguishable classes of indistinguishable

Michael Hardy

2006-01-01

303

On higher derivative gravity  

Microsoft Academic Search

A possible classical route conducting towards a general relativity theory with higher-derivatives starting, in a sense, from first principles, is analysed. A completely causal vacuum solution with the symmetries of the Goedel universe is obtained in the framework of this higher-derivative gravity. This very peculiar and rare result is the first known vacuum solution of the fourth-order gravity theory that

A. J. Accioly

1987-01-01

304

Derivative beliefs and evaluations  

Microsoft Academic Search

Purpose – The purpose of this research is to examine how consumers form beliefs and evaluate derivatives (e.g. handheld computers) and branded derivatives (e.g. Palm handheld computers). The aim is to study how consumers combine two categories (e.g. “handheld products” and “computers”) to form beliefs, how the similarity between the categories influences beliefs, how the addition of a brand changes

Daniel A. Sheinin; Laurette Dubé; Bernd H. Schmitt

2008-01-01

305

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

306

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

307

Crosslinkable cellulose derivatives  

SciTech Connect

This patent describes a method for treating a subterranean formation. It comprises: preparing a treating fluid composition with or without a particulate agent by admixing an aqueous liquid, a cellulose ether derivative consisting essentially of the reaction product of a cellulose ether with a ceric salt, the reaction occurring under acidic conditions and at a temperature in the range of from about 20{degree} to about 60{degree}C. and a cross-linking agent; and injecting the treating fluid composition into the subterranean formation through a wellbore. This patent also describes a method of treating a subterranean formation. It comprises: preparing a treating fluid composition with or without a particulate agent by admixing an aqueous liquid, a cellulose ether derivative that is chemically modified by reacting under acidic conditions the cellulose ether derivative with a vinyl phosphonic acid and a ceric salt, and a crosslinking agent; and injecting the treating fluid composition into the subterranean formation through a wellbore.

Holtmeyer, M.D.; Hunt, C.V.; Harms, W.M.

1991-01-08

308

Novel derivatives of polymyxins.  

PubMed

Polymyxin B and colistin (polymyxin E) are bactericidal pentacationic lipopeptides that act specifically on Gram-negative bacteria, first by disrupting their outermost permeability barrier, the outer membrane (OM), and then damaging the cytoplasmic membrane. Both were discovered in the mid-1950s and subsequently used in intravenous therapy, but soon largely abandoned because of nephrotoxicity. The emergence of extremely multiresistant strains has now forced clinicians to reinstate them in the therapy of severe infections caused by such strains. This article reviews recent attempts to develop novel derivatives of polymyxins that exhibit less toxicity and greater potency than the existing drugs. In addition, studies of novel des-fatty acyl-polymyxin derivatives that display activity against Pseudomonas aeruginosa are included. The review also covers recent studies of derivatives that lack potent bactericidal action, but which disrupt the OM, which increases bacterial permeability to other antibiotics, facilitating their entry into the cell. PMID:23412346

Vaara, Martti

2013-02-13

309

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

310

Crosslinkable cellulose derivatives  

SciTech Connect

This paper reports method of treating a subterranean formation. It comprises: preparing a treating fluid composition with or without a particulate agent by admixing: an aqueous liquid, a cellulose ether derivative that is chemically modified by reacting the cellulose ether derivative with a vinyl phosphonic acid in the presence of the reaction product of hydrogen peroxide and a ferrous salt and a crosslinking agent; and injecting the treating fluid composition into the subterranean formation through a wellbore; injecting the treating fluid composition into the subterranean formation through a wellbore.

Holtmyer, M.; Hunt, C.V.

1991-11-26

311

Credit Derivatives and Risk Management.  

National Technical Information Service (NTIS)

The striking growth of credit derivatives suggests that market participants find them to be useful tools for risk management. I illustrate the value of credit derivatives with three examples. A commercial bank can use credit derivatives to manage the risk...

M. S. Gibson

2007-01-01

312

Deriving Function From Structure  

Microsoft Academic Search

\\u000a The fold and biochemical activity of a protein are tightly coupled. Once a protein is characterized, it is usual to determine\\u000a its structure in order to derive an atomic descrip- tion of its molecular mechanism. The fold reveals interaction surfaces,\\u000a ligand-binding pockets, and the precise juxtaposition of functional groups.

Annabel E. Todd

313

SCIENTIFIC OPINION Flavouring Group Evaluation 54, Revision 1 (FGE.54Rev1): Consideration of benzyl derivatives evaluated by JECFA (57 th meeting) structurally related to benzyl alcohols, benzaldehydes, a related acetal, benzoic acids and related esters evaluated by EFSA in FGE.20Rev1 (2009) 1  

Microsoft Academic Search

SUMMARY The Scientific Panel on Food Food Contact Materials, Enzymes, Flavourings and Processing Aids (the Panel) was asked to provide scientific advice to the Commission on the implications for human health of chemically defined flavouring substances used in or on foodstuffs in the Member States. In particular, the Panel was requested to consider the Joint FAO\\/WHO Expert Committee on Food

Arturo Anadon; David Bell; Mona-Lise Binderup; Wilfried Bursch; Laurence Castle; Karl-Heinz Engel; Roland Franz; Nathalie Gontard; Thomas Haertle; Trine Husøy; Catherine Leclercq; Jean Claude Lhuguenot; Wim Mennes; Maria Rosaria Milana; Karla Pfaff; Kettil Svensson; Fidel Toldra; Rosemary Waring

2009-01-01

314

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

315

Adipose-derived cells.  

PubMed

Heart failure is by far the most common cause of hospitalization in Western countries, with onerous economic consequences. Cell therapy holds great promise for use in tissue regeneration and is increasingly used in an effort to improve outcomes in cardiac disease. Recently it has been shown that adipose tissue, in addition to committed adipogenic, endothelial progenitor cells and pluripotent vascular progenitor cells, also contains multipotent cell types (adipose-derived stem cells, ADSCs) that, in cell culture conditions, have shown to have an impressive developmental plasticity including the ability to undergo multilineage differentiation and self-renewal. ADSCs express multiple CD marker antigens similar to those observed on MSCs and are also capable of secreting a large number of angiogenesis-related cytokines, including vascular endothelial growth factor, granulocyte/macrophage colony stimulating factor, stromal-derived factor-1alpha, and hepatocyte growth factor. Adipose tissue can be harvested in large quantities with minimal morbidity in several regions of the body and, on average, 100 ml of human adipose tissue yields about 1 x 10(6) stem cells. Studies conducted in porcine AMI models have shown a significant LV functional improvement, with no report of any potentially fatal arrhythmias. The APOLLO trial, a prospective, double blind, randomized, placebo-controlled trial currently in the recruiting phase, is a "first-in-man" study that explores the safety and feasibility of ADSC transplantation in patients with acute MI. PMID:18293895

Meliga, Emanuele; Strem, Brian M; Duckers, H J; Serruys, Patrick W

2007-01-01

316

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

317

Derivative Analysis of Hyperspectral Data  

Microsoft Academic Search

With the goal of applying derivative spectral analysis to analyze high-resolution, spectrally continuous remote sensing data, several smoothing and derivative computation algorithms have been reviewed and modified to develop a set of cross-platform spectral analysis tools. Emphasis was placed on exploring different smoothing and derivative algorithms to extract spectral details from spectral data sets. A modular program was created to

Fuan Tsai; William Philpot

1998-01-01

318

Derivative spectrophotometry of cobalt alloys  

Microsoft Academic Search

The method of derivative spectrophotometry is briefly described, and derivative absorption spectra are presented for samarium, cobalt, and commercial Sm-Co alloys. It is shown that the use of derivative spectrophotometry not only improves the accuracy and selectivity of element determinations but also simplifies the analysis of alloys. Results of a statistical evaluation of the metrological characteristics of the analytical procedure

Spitsyn

1985-01-01

319

4-(Prop-2-yn-1-yl-oxy)benzaldehyde  

PubMed Central

In the title mol­ecule, C10H8O2, all non-H atoms are essentailly coplanar (r.m.s. deviation = 0.0192?Å), indicating an effective conjugation of the carbonyl group, the benzene ring and the lone pair of the propyn­yloxy O atom. In the crystal, ?–? stacking inter­actions [centroid–centroid distance = 3.5585?(15)?Å] connect mol­ecules into inversion dimers which are linked by Csp—H?O=C hydrogen bonds, forming a ladder-like structure.

Doi, Ikue; Okuno, Tsunehisa

2013-01-01

320

Tripyrroledimethine-derived  

Microsoft Academic Search

The syntheses of three new cadmium(II)-containing tripyrroledimethine-derived, 'texaphyrin'-type, macrocycles, 14,15-dicyano-4,5,9,20-tetraethyl-10,19-dimethyl-13,16,21,22,23- pentazatetracyclo[16.2 .1.13,6.18,11]tricosa-1,3,5,7,9,11(23)12,14,16,18(21),19-undecaene (1), 4,5,9,28-tetraethyl-10,27-dimethyl-13,24,29,30,31- pentaazahexaacyclo$B24.2.1.13,6. 18,11.014,23.016,21]-hentriaconta-1,,5,7,9,11(31),12,14(23),15,17,19, 21,24,26(29),27-pentadecaene (2), and 4,5,9,32-tetraethyl-10,31-dimethyl-13,28,33,34,35- pentaazaheptacyclo$B28.2.1.13,6. 18,11.014,27.015,20.021,26]pentariconta-1,3,5,7,9,11(35),12,14( 27),15(20),16,18,21(26),22,24,28,30(33,31-heptadecaene (3), are discussed. These compounds, which contain extended (pi) -systems, possess strong, low-energy, Q-like absorption bands in the 650-900 nm spectral region, making them of possible interest in photodynamic applications. Time-resolved absorption and emission laser studies have

Jonathan L. Sessler; Gregory Hemmi; Bhaskar G. Maiya; Anthony Harriman; Millard M. Judy; Richard L. Boriak; James Lester Matthews; Benjamin Ehrenberg; Zvi Malik; Yeshayahu Nitzan; Angelika C. Rueck

1991-01-01

321

Deriving bedform phase diagrams  

NSDL National Science Digital Library

Students prepare for this activity by working with a unidirectional flume with a sand bed. We adjust water depth, flow velocity, and channel slope to achieve a range of bed states, in an effort for them to understand the controls on bedforms. This portion of the activity could be done in lecture or via another exercise that makes use of digital video of actual experiments. The activity itself is a jigsaw: students form groups of three, each group responsible for plotting depth vs. velocity plots of bedform state for a single sand grain size range (0.10-0.14 mm, 0.5-0.64 mm, and 1.3-1.8 mm). These data are provided to them as Excel files and the data were directly 'stolen' from the original depth vs. velocity plots in Middleton and Southard (1984), Mechanics of Sediment Movement, SEPM Short Course Number 3. Datathief software (available free on the web) was used to steal the data. The data are arranged in columns: depth, velocity, and bedform type. Students must plot each of the different bedform types with a different symbol, then they have to define field boundaries. It is critical that they have never seen the original plots in their textbook. The goal is for them to derive them on their own, not to regurgitate what is in their textbook or elsewhere. After they complete their plots for each grain size range, the groups re-arrange themselves into groups of three with one representative from each of the grain size groups. They then must try to evaluate the effects of changing grain size on bedform state. Finally, after completing the exercise, the bedform analysis is linked to the cross stratification that is produced under conditions of high sediment fallout rates and the given bed state. The activity gives students practice working with realistic datasets, exposure to the role of physical modeling in sedimentary geology, and a chance to plot and interpret real data. Furthermore, it really solidifies the link between cross stratification and its dynamic interpretation from the rock record.

Hickson, Thomas

322

Key Derivation and Randomness Extraction  

Microsoft Academic Search

Key derivation refers to the process by which an agreed upon large random number, often named master secret, is used to derive keys to encrypt and authenticate data. Practitioners and standard- ization bodies have usually used the random oracle model to get key material from a Die-Hellman key exchange. However, proofs in the standard model require randomness extractors to formally

Olivier Chevassut; Pierre-Alain Fouque; Pierrick Gaudry; David Pointcheval

2005-01-01

323

21 CFR 184.1685 - Rennet (animal-derived) and chymosin preparation (fermentation-derived).  

Code of Federal Regulations, 2010 CFR

...animal-derived) and chymosin preparation (fermentation-derived). 184.1685 Section...animal-derived) and chymosin preparation (fermentation-derived). (a)(1...4.23.4). It is derived, via fermentation, from a nonpathogenic and...

2010-01-01

324

21 CFR 184.1685 - Rennet (animal-derived) and chymosin preparation (fermentation-derived).  

Code of Federal Regulations, 2010 CFR

...animal-derived) and chymosin preparation (fermentation-derived). 184.1685 Section...animal-derived) and chymosin preparation (fermentation-derived). (a)(1...4.23.4). It is derived, via fermentation, from a nonpathogenic and...

2009-04-01

325

MCR synthesis of praziquantel derivatives.  

PubMed

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. PMID:22151001

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

2012-01-30

326

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

327

Deriving Laws from Ordering Relations.  

National Technical Information Service (NTIS)

The effect of Richard T. Cox's contribution to probability theory was to generalize Boolean implication among logical statements to degrees of implication, which are manipulated using rules derived from consistency with Boolean algebra. These rules are kn...

K. H. Knuth

2004-01-01

328

CB2-Selective Cannabinoid Derivatives.  

National Technical Information Service (NTIS)

Cannabinoid derivatives that exhibit specificity for the CB(sub 2) cannabinoid receptor are provided. The analogues are tetrahydrocannabinols and hydroxyhexahydrocannabinols, and are useful for the treatment of pain, inflammation, and cancer.

B. R. Martin J. W. Huffman M. I. Damaj

2005-01-01

329

Topological Derivatives in Plane Elasticity  

Microsoft Academic Search

We present a method for construction of the topological derivatives in plane elasticity. It is assumed that a hole is created\\u000a in the subdomain of the elastic body which is filled out with isotropic material. The asymptotic analysis of elliptic boundary\\u000a value problems in singularly perturbed geometrical domains is used in order to derive the asymptotics of the shape functionals

Jan Sokolowski; Antoni Zochowski

2007-01-01

330

Citrinin derivatives from the marine-derived fungus Penicillium citrinum.  

PubMed

Three new citrinin derivatives, penicitrinols C, D, and E (1-3), along with two known compounds, citrinin (4) and decarboxydihydrocitrinone (5), were isolated from Penicillium citrinum. Their structures were determined by spectroscopic methods and X-ray diffraction analysis. Compounds 1 and 3 demonstrated weak cytotoxicity against the HL-60 cell line. PMID:21467687

Chen, Li; Liu, Wei; Hu, Xiao; Huang, Kai; Wu, Jiu-Lin; Zhang, Qi-Qing

2011-01-01

331

"Clickable" vitamin B12 derivative.  

PubMed

A "clickable" vitamin B12 derivative possessing the azide functionality at the 5'-position was synthesized by means of a two-step procedure on the gram scale. The reaction of cobalamin with mesyl chloride (MsCl) afforded the 5'-OMs derivative, which was subsequently transformed to the desired 5'-azide, the structure of which was confirmed using X-ray analysis. It proved to be reactive in the azide-alkyne 1,3-dipolar cycloaddition reaction to give substituted triazoles in high yields. A study of the reaction conditions and the scope of the process are reported. PMID:23325459

Chromi?ski, Miko?aj; Gryko, Dorota

2013-01-16

332

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

333

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

334

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

335

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

336

Synthesis of 3-aminopyridine-2-carboxaldehyde thiosemicarbazone (3AP)  

Microsoft Academic Search

Palladium-catalyzed cross-coupling of methylboronic acid with 2-chloro-3-nitropyridine produced 2-methyl-3-nitropyridine 4 in one step in high yield. Oxidation of 4 with selenium dioxide gave aldehyde 5. Alternatively, condensation of 4 with DMFDMA followed by oxidation gave 5 in a two step higher yielding conversion. Subsequent direct coupling of 5 with thiosemicarbazide followed by reduction of the nitro group using stannous chloride

Chuansheng Niu; Jun Li; Terrence W. Doyle; Shu-Hui Chen

1998-01-01

337

Quinuclidine Derivatives as Potential Antiparasitics  

Microsoft Academic Search

There is an urgent need for the development of new drugs for the treatment of tropical parasitic diseases such as Chagas' disease and leishmaniasis. One potential drug target in the organisms that cause these diseases is sterol biosynthesis. This paper describes the design and synthesis of quinuclidine derivatives as potential inhibitors of a key enzyme in sterol biosynthesis, squalene synthase

Simon B. Cammerer; Carmen Jimenez; Simon Jones; Ludovic Gros; Silvia Orenes Lorente; Carlos Rodrigues; Juliany C. F. Rodrigues; Aura Caldera; Luis Miguel Ruiz Perez; Wanderley da Souza; Marcel Kaiser; Reto Brun; Julio A. Urbina; Dolores Gonzalez Pacanowska; Ian H. Gilbert

2007-01-01

338

Shuttle derived unmanned launch vehicle  

Microsoft Academic Search

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

D. N. Buell; J. R. Tewell

1985-01-01

339

New hydrophobically modified carboxymethylcellulose derivatives  

Microsoft Academic Search

New hydrophobically substituted carboxymethylcellulose derivatives with different percentages of modification by hexadecylamine (from 0.9 to 6% per monomeric unit acid group) were obtained by amidation of the carboxyl group by different methods. The percentage of modification (% HDA) was controlled by conductimetric titration and quantitative 13C NMR spectra on cellulase hydrolyzed oligomers. The least degradation (checked by GPC measurements), was

D. Charpentier; G. Mocanu; A. Carpov; S. Chapelle; L. Merle; G. Müller

1997-01-01

340

Deriving Safety Requirements Using Scenarios  

Microsoft Academic Search

Elicitation of requirements for safety critical aero- engine control systems is dependent on the capture of core design intent and the systematic derivation of requirements addressing hazardous deviations from that intent. Deriva- tion of these requirements is inextricably linked to the safety assessment process. Conventional civil aerospace prac- tice (as advocated by guidelines such as ARP4754 and ARP4671) promotes the

Karen Allenby; Tim Kelly

2001-01-01

341

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

342

Dimeric avermectin and milbemycin derivatives  

US Patent & Trademark Office Database

This invention provides for novel antiparasitic and pesticidal derivatives of avermectin and milbemycin compounds in which two avermectin or milbemycin members are linked together by a chemical linker. The resulting compounds may be used in veterinary compositions which are used in treating, controlling and preventing of endo- and ectoparasite infections and infestations in animals or for combating pests in plants or plant propagation material.

Meng; Charles Q. (Johns Creek, GA)

2013-04-23

343

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

344

Lie Derivatives and Dynamical Systems  

Microsoft Academic Search

Applications of Lie derivatives in chaos synchronization and localization of periodic orbits are discussed. We present examples illustrating how one can construct a system that synchronizes with a given dynamical system, and how one can find a set that contains all periodic orbits of a dynamical system.

Ljupco Kocarev; Ulrich Parlitz; Bambi Hu

1998-01-01

345

Derived Categories and Lie Algebras  

Microsoft Academic Search

Let $\\\\md^b(A)$ be the derived category of a finite dimensional basic algebra $A$ with finite global dimension. We construct the Lie algebra arising from the 2-periodic version $\\\\mk_2(\\\\mp(A))$ of $\\\\mk^b(\\\\mp(A))$ in term of constructible functions on varieties attached to $\\\\mk_2(\\\\mp(A))$.

Jie Xiao; Fan Xu; Guanglian Zhang

2006-01-01

346

Anti-Leishmanial Lepidine Derivatives.  

National Technical Information Service (NTIS)

The subject 8-amino-6-methoxy lepidine derivatives have the formula: wherein, R represents an --alkylene (tertiary) amine, --alkylene-NH2, (N-alkylsubstituted piperadyl amino)-alkylene-, --alkylene-(tertiary) amine or -- alkylene-N-heterocyclic; R1, repre...

K. E. Kinnamon

1980-01-01

347

Alchemical derivatives of reaction energetics.  

PubMed

Based on molecular grand canonical ensemble density functional theory, we present a theoretical description of how reaction barriers and enthalpies change as atoms in the system are subjected to alchemical transformations, from one element into another. The change in the energy barrier for the umbrella inversion of ammonia is calculated along an alchemical path in which the molecule is transformed into water, and the change in the enthalpy of protonation for methane is calculated as the molecule is transformed into a neon atom via ammonia, water, and hydrogen fluoride. Alchemical derivatives are calculated analytically from the electrostatic potential in the unperturbed system, and compared to numerical derivatives calculated with finite difference interpolation of the pseudopotentials for the atoms being transformed. Good agreement is found between the analytical and numerical derivatives. Alchemical derivatives are also shown to be predictive for integer changes in atomic numbers for oxygen binding to a 79 atom palladium nanoparticle, illustrating their potential use in gradient-based optimization algorithms for the rational design of catalysts. PMID:20815557

Sheppard, Daniel; Henkelman, Graeme; von Lilienfeld, O Anatole

2010-08-28

348

Combustion of Waste Derived Fuel.  

National Technical Information Service (NTIS)

Over the past decade Warren Spring Laboratory has been involved in programs to investigate various aspects of the incineration of waste and the use of Refuse Derived Fuel (RDF). Investigations were carried out to assess the suitability of RDF for combusti...

B. J. Davis P. Clayton

1984-01-01

349

Revised derivation of Landau damping  

Microsoft Academic Search

We re-derive Landau's damping equation using an alternative method different from that of the original author. This alternative method results in a factor of two greater damping. This factor of two is a result of inconsistent assumptions by Landau about the nature of the singularity.

IGOR ALEXEFF; MARK RADER

1990-01-01

350

CRYSTALLINE ACETYL DERIVATIVES OF PEPSIN  

PubMed Central

Crystalline pepsin has been acetylated by the action of ketene in aqueous solution at pH 4.07–5.5. As acetylation proceeds the activity decreases, the decrease being more rapid at pH 5.0–5.5 than at 4.0–4.5. Three acetyl derivatives have been isolated from the reaction mixture and obtained in crystalline form. The crystal form of these derivatives is similar to that of pepsin. Fractionation and solubility determinations show that these preparations are not mixtures or solid solutions of the original pepsin with an inactive derivative. A compound which contains three or four acetyl groups and which has lost all of its original primary amino groups can be isolated after short acetylation. It has the same activity as the original pepsin. A second derivative containing six to eleven acetyl groups has also been isolated. It has about 60 per cent of the activity of the original pepsin. A third derivative having twenty to thirty acetyl groups and about 10 per cent of the activity of original pepsin can be isolated after prolonged acetylation. The 60 per cent active derivative on standing in strong acid solution loses some of its acetyl groups and at the same time regains the activity of the original pepsin. The compound obtained in this way is probably the same as the completely active three acetyl derivative obtained by mild acetylation. These results show that acetylation of three or four of the primary amino groups of pepsin causes no change in the specific activity of the enzyme but that the introduction of acetyl groups in other parts of the molecule results in a marked loss in activity. The solubilities, amino nitrogen content, acetyl content, isoelectric point, and the specific activity have been determined by a variety of methods and found to be different from the corresponding properties of crystalline pepsin. The pH-activity curves, acid and alkali inactivation, and titration curves were not significantly different from the same respective properties of pepsin.

Herriott, Roger M.; Northrop, John H.

1934-01-01

351

Columbus service vehicle and derivatives  

NASA Astrophysics Data System (ADS)

When Columbus phase B1 started in early 1985 the Service Vehicle (SV) was one of the four candidate elements to be developed by Europe in the frame of the U.S. Space Station program. The present paper will briefly summarize the main results achieved on the SV after phase B1 completion. It will also provide data on some SV derivatives which are currently under study, and particularly one resulting actually from an adaptation of this SV to a more European autonomous environment relying exclusively upon the use of Ariane and Hermes launchers: the so-called Ariane Transfer Vehicle (ATV). An other derivative is an answer to the manned space interventions issue, an intermediate concept betwen a manned SV and an astronaut with its ancilliary devices (e.g. Manned Maneuvering Unit).

Eymar, P.

1986-10-01

352

Plant-derived wildlife repellents  

US Patent & Trademark Office Database

Products from the plant species Nerium oleander and, Urginea maritima, are prepared and tested as wildlife repellents comparing them with digitalis products. Chemical compounds derived from these plants including oleandrin, oleandrigenin, scillirosidin, digitoxigenin and digoxigenin are shown to cause nausea and emesis at low doses in pigeons and to repel, mice, rats, gophers, meadow voles and mountain beavers. After ingestion these animals quickly learn to avoid targets treated with the plant-derived repellents. When the remembrance of a treated food or other target lasts for an extended period of time it can be termed an aversion conditioning agent. Such products can be used for the protection of other plants, seeds, buildings, structures, communication cables and animals exposed to wildlife.

Verbiscar; Anthony J. (Sierra Madre, CA)

1994-10-18

353

Photophysical characterization of fluorenone derivatives  

Microsoft Academic Search

The photophysics of several fluorenone derivatives was studied using fluorescence and laser-induced optoacoustic spectroscopy. Electron-donating substituents increase the energy of the key upper triplet state (T3) which, for the parent compound, is responsible for the increased intersystem crossing quantum yield in non-polar solvents. Electron-withdrawing substituents decrease the energy of T3, and an increase in the intersystem crossing rate constant is

R. S. Murphy; C. P. Moorlag; W. H. Green; C. Bohne

1997-01-01

354

Massive Higher Derivative Gravity Theories  

Microsoft Academic Search

In this thesis massive higher derivative gravity theories are analyzed in some detail. One-particle scattering amplitude between two covariantly conserved sources mediated by a graviton exchange is found at tree-level in $D$ dimensional (Anti)-de Sitter and flat spacetimes for the most general quadratic curvature theory augmented with the Pauli-Fierz mass term. From the amplitude expression, the Newtonian potential energies are

Ibrahim Gullu

2012-01-01

355

Berberine derivatives as antileishmanial drugs.  

PubMed Central

Berberine, a quaternary alkaloid, and several of its derivatives were tested for efficacy against Leishmania donovani and Leishmania braziliensis panamensis in golden hamsters. Tetrahydroberberine was less toxic and more potent than berberine against L. donovani but was not as potent as meglumine antimonate (Glucantime), a standard drug for the treatment of leishmaniasis. Only berberine and 8-cyanodihydroberberine showed significant activity (greater than 50% suppression of lesion size) against L. braziliensis panamensis.

Vennerstrom, J L; Lovelace, J K; Waits, V B; Hanson, W L; Klayman, D L

1990-01-01

356

Microglia-derived cytotoxic factors  

Microsoft Academic Search

The rarity of neoplasms in the adult mammalian retina has led us to hypothesize the presence or increased expression of `tumor-inhibitory molecules' in the mature differentiated retina. We have begun to investigate the source(s) of these molecules, and the following study describes the inhibitory activity of a soluble microglia-derived cytotoxic factor on the proliferation of C6 cells, a glial tumor

Armando A Rosales; Rouel S Roque

1997-01-01

357

Higher-derivative Quantum Cosmology  

Microsoft Academic Search

The quantum cosmology of a higher-derivative gravity theory arising from the heterotic string effective action is reviewed. A new type of Wheeler–DeWitt equation is obtained when the dilaton is coupled to the quadratic curvature terms. Techniques for solving the Wheeler–DeWitt equation with appropriate boundary conditions shall be described, and implications for semiclassical theories of inflationary cosmology will be outlined.

Simon Davis

2000-01-01

358

Resurgence of derived stimulus relations  

Microsoft Academic Search

Resurgence has been shown in human and nonhuman operant behavior, but not in derived rela- tional responses. The present study examined this issue. Twenty-three undergraduates were trained to make conditional discriminations in a three-choice matching-to-sample paradigm. The training resulted in three equivalence classes, each consisting of four arbitrarily configured visual stimuli. The same 12 stimuli were then reorganized, and the

KELLY G. WILSON; STEVEN C. HAYES

1996-01-01

359

SOME DERIVATIVES OF NEWTON'S METHOD  

Microsoft Academic Search

Every first-year calculus student learns Newton's method as part of a repertoire of numerical root-finding methods. We present two other numerical root-finding methods that we derive using Newton's method: a simplified Newton's method, and Halley's method. These two methods are not new, yet they seldom find their way into a first calculus course even though they would not be out

J. B. Thoo

2002-01-01

360

Some Derivatives of Newton's Method  

Microsoft Academic Search

Every rst-year calculus student learns Newton's method as part of a repertoire of numerical root-nding methods. We present two other numerical root-nding methods that we derive using Newton's method: a simplied Newton's method, and Halley's method. These two methods are not new, yet they seldom nd their way into a rst calculus course even though they would not be out

J. B. Thoo

2001-01-01

361

Vibration spectra of complexes of rare earth nitrate with some Schiff bases  

NASA Astrophysics Data System (ADS)

Infrared and Raman spectra of complexes of rare earth nitrate with Schiff bases derived from vanillin (3-methoxy-4-hydroxy-benzaldehyde) or o-vanillin (2-hydroxy-3-methoxy-benzaldehyde) and p-toluidine, 1-naphthylamine, 2-naphthylamine are reported.

Guofa, Liu

1994-06-01

362

Spectral, magnetic, biocidal screening, DNA binding and photocleavage studies of mononuclear Cu(II) and Zn(II) metal complexes of tricoordinate heterocyclic Schiff base ligands of pyrazolone and semicarbazide\\/thiosemicarbazide based derivatives  

Microsoft Academic Search

We depict the synthesis and characterization of copper(II) and zinc(II) coordination compounds of 4-(3?,4?-dimethoxybenzaldehydene)2-3-dimethyl-1-phenyl-3-pyrazolin-5-semicarbazone (1a), 4-(3?,4?-dimethoxybenzaldehydene)2-3-dimethyl-1-phenyl-3-pyrazolin-5-thiosemicarbazone (1b), 4-(3?-hydroxy-4?-nitrobenzaldehydene)2-3-dimeth yl-1-phenyl-3-pyrazolin-5-semicarbazone (1c) and 4-(3?-hydroxy-4?-nitrobenzal dehydene)2-3-dimethyl-1-phenyl-3-pyrazolin-5-thiosemicarbazone (1d). All the remote compounds have the general composition [ML2] (M=Cu(II) and Zn(II)); L=Schiff base (1a–1d). All the complexes were characterized by elemental analysis, molar conductivity, IR, 1H NMR, UV–vis, ESI-Mass, magnetic susceptibility measurements, cyclic voltammetric measurements,

N. Raman; A. Selvan; P. Manisankar

2010-01-01

363

Deriving projective hyperspace from harmonic  

SciTech Connect

We derive actions for projective N=2 superspace ('hyperspace') from those for harmonic hyperspace, including that for non-Abelian Yang-Mills theory (a new result). The method uses Wick rotation of the sphere from complex conjugate coordinates to real, null ones, which can be treated as independent. The result can be considered 'holographic' in that the dimension of the internal (R symmetry) space is reduced from 2 to 1, by solving equations of motion or gauge conditions for dependence on the other coordinate. The auxiliary nature of the redundant dimension makes the hypergraph rules and evaluation almost identical.

Jain, Dharmesh; Siegel, Warren [C. N. Yang Institute for Theoretical Physics, State University of New York, Stony Brook, New York 11794-3840 (United States)

2009-08-15

364

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); Venables, Barney J. (Denton, TX); Ohlsson, Oscar O. (Naperville, IL)

1996-01-01

365

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

366

Diagrammatic derivation of Lovelock densities  

SciTech Connect

We discuss a method of calculating the various scalar densities encountered in Lovelock theory, which relies on diagrammatic, instead of algebraic manipulations. Taking advantage of the known symmetric and antisymmetric properties of the Riemann tensor that appears in the Lovelock densities, we map every quadratic or higher contraction into a corresponding permutation diagram. The derivation of the explicit form of each density is then reduced to identifying the distinct diagrams, from which we can also read off the overall combinatoric factors. The method is applied to the first Lovelock densities, of order two (Gauss-Bonnet term) and three.

Bogdanos, C. [Laboratoire de Physique Theorique, Universite de Paris-Sud 11, Batiment 210, 91405 Orsay CEDEX (France)

2009-05-15

367

Deriving projective hyperspace from harmonic  

NASA Astrophysics Data System (ADS)

We derive actions for projective N=2 superspace (“hyperspace”) from those for harmonic hyperspace, including that for non-Abelian Yang-Mills theory (a new result). The method uses Wick rotation of the sphere from complex conjugate coordinates to real, null ones, which can be treated as independent. The result can be considered “holographic” in that the dimension of the internal (R symmetry) space is reduced from 2 to 1, by solving equations of motion or gauge conditions for dependence on the other coordinate. The auxiliary nature of the redundant dimension makes the hypergraph rules and evaluation almost identical.

Jain, Dharmesh; Siegel, Warren

2009-08-01

368

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

369

Resurgence of derived stimulus relations.  

PubMed Central

Resurgence has been shown in human and nonhuman operant behavior, but not in derived relational responses. The present study examined this issue. Twenty-three undergraduates were trained to make conditional discriminations in a three-choice matching-to-sample paradigm. The training resulted in three equivalence classes, each consisting of four arbitrarily configured visual stimuli. The same 12 stimuli were then reorganized, and the conditional discrimination training was repeated such that three new classes were possible. In a subsequent test of derived relations, most subjects showed response patterns that were consistent with the altered conditional discriminations. Subjects were then exposed to conditional discrimination trials under extinction. Most subjects continued to respond consistently with the most recently reinforced conditional discrimination trials. During the next phase, subjects were exposed to symmetry and equivalence trials. Responses consistent with the most recent training produced feedback saying that the responses were incorrect, whereas other responses produced no feedback. Most subjects showed a resurgence of responding that was consistent with their earlier training. Finally, subjects were exposed to conditional discrimination trials carried out in extinction. Most subjects continued to show a resurgence of responding that was consistent with their early training.

Wilson, K G; Hayes, S C

1996-01-01

370

Fourth order spatial derivative gravity  

NASA Astrophysics Data System (ADS)

In this work, we study a modified theory of gravity that contains up to fourth order spatial derivatives as a model for the Ho?ava-Lifshitz gravity. The propagator is evaluated and, as a result, one extra pole is obtained, corresponding to a spin-2 nonrelativistic massless particle, an extra term which jeopardizes renormalizability, besides the unexpected general relativity unmodified propagator. Then unitarity is proved at the tree level, where the general relativity pole has been shown to have no dynamics, remaining only the 2 degrees of freedom of the new pole. Next, the nonrelativistic effective potential is determined from a scattering process of two identical massive gravitationally interacting bosons. In this limit, Newton’s potential is obtained, together with a Darwin-like term that comes from the extra nonpole term in the propagator. Regarding renormalizability, this extra term may be harmful by power counting, but it can be eliminated by adjusting the free parameters of the model. This adjustment is in accord with the detailed balance condition suggested in the literature and shows that the way in which extra spatial derivative terms are added is of fundamental importance.

Bemfica, F. S.; Gomes, M.

2011-10-01

371

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

Code of Federal Regulations, 2013 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...

2013-07-01

372

Chromatography of coal derived products: general papers  

SciTech Connect

Twenty papers presented at the Symposium on Chromatography of Coal Derived Products are abstracted separately. These covered liquid column chromatography and gas chromatography/mass spectroscopy for separation and characterization of coal derived products.

Not Available

1981-01-01

373

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

374

Treatment of Cancer Using Benzoic Acid Derivatives.  

National Technical Information Service (NTIS)

The present invention provides a method of treating cancer using benzoic acid derivatives, alone or in combination with standard treatments such as chemotherapy and radiotherapy. Also provided are methods of screening for benzoic derivatives based on thei...

D. Morais D. Rodriquez L. Liebes P. C. Brooks

2005-01-01

375

New, Water Soluble, Antineoplastic Derivatives of Taxol.  

National Technical Information Service (NTIS)

The invention is related to new, water soluble derivatives of taxol with antineoplastic activity. More particularly, the invention is related to 2'-0-acyl derivatives of taxol with improved water solubility while retaining antineoplasic property of the pa...

R. D. Haugwitz L. Zalkow J. Glinski M. Suffness H. M. Deutsch

1988-01-01

376

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

377

Substituted N-Methyl Derivatives of Mitindomide.  

National Technical Information Service (NTIS)

The present invention relates to certain derivatives of diimidestatin (mitindomide) which is a photosynthetic addition product of benzene and maleimide. More particularly, the present invention relates to N-methyl derivatives of diimidestatin and methods ...

R. D. Haugwitz V. L. Narayanan L. H. Zalkow H. M. Deutsch

1987-01-01

378

Blunt-Cone Roll-Damping Derivative.  

National Technical Information Service (NTIS)

The roll-damping derivative is one of the many aerodynamic coefficients that influence the flight dynamics of a rolling missile. At present, the knowledge of this derivative is limited, especially for unfinned bodies of revolution in hypersonic flight. Th...

B. Quinn

1968-01-01

379

Thermodynamic Partial Derivatives and Experimentally Measurable Quantities.  

ERIC Educational Resources Information Center

|Proposed is a flow-chart and related formulas to obtain expressions for the derivatives of the old thermodynamic function in terms of new variables, the new function and its derivatives, and derivatives of the old function, involving only measurable quantities. (CW)|

Estevez, Gentil A.; And Others

1989-01-01

380

Derivative unfolding by spline techniques  

NASA Astrophysics Data System (ADS)

This paper presents some possible improvements to the derivative unfolding scheme employed in processing recoil proton data to obtain the neutron spectra. The scheme is based on representing the recoil proton spectrum by means of equally spaced cubic bell-splines. The finite spread in the detector response to monoenergetic protons is accounted for by folding the splines suitably. A code based on this formulation has been tested with trial spectra pertaining to standard neutron sources such as Pu-Be and has performed better in terms of resolution and of accuracy of the predicted peak positions. The current formulation is flexible for adding constraints using a priori information. This is demonstrated with respect to the suppression of spurious oscillations occurring near the high energy end of the spectra. This scheme is restricted to continuous spectra, however.

Subbaiah, K. V.; Natarajan, A.

1985-01-01

381

Optical nonlinearities of perylene derivatives  

NASA Astrophysics Data System (ADS)

Nonlinear optical properties of perylene derivatives were studied by femtosecond Z-scan technique. 3,4,9,10-Perylenetetracarboxylic dianhydride (PTCDA), 3,4,9,10-perylenetetracarboxylic diimide (PTCDI), and perylene-66 (dibenzthiophenoperylene-N,N'-dicyclohexylimide), were studied. Tetrahydrofuran was used as a solvent for perylene- 66. The solubility of PTCDA and PTCDI is very poor. Their colloidal solution was prepared by the irradiation of the third harmonics of a pulsed YAG laser to opaque suspension of PTCDA and PTCDI. Transparent colloidal solution was obtained within 50 minutes of UV irradiation. Colloidal solution of quinacridone was also studied. Two-photon absorption cross sections of these dyes were measured by open aperture Z-scan method using a femtosecond laser. The dependence of two-photon cross section on laser wavelength was measured in the wavelength range of 780-820 nm.

Sasaki, Yoshihiko; Takamo, Hiroyuki; Kasatani, Kazuo

2008-01-01

382

Anti-cancer quinazoline derivatives  

US Patent & Trademark Office Database

Quinazoline derivatives of formula: ##STR1## wherein R represents: (1) a straight or branched chain unsaturated hydrocarbon group, or (2) a straight or branched chain saturated or unsaturated hydrocarbon group which is substituted by at least one: heteroatom, the or each heteroatom being halogeno when R is a C.sub.1 hydrocarbon group; or saturated carbocyclic group; or group containing at least one heteroatom, the or each heteroatom being O, N or S when R contains a cyclic group; and n is 0 or an integer of 1-4; X or, when n is an integer of at least 2, each X independently, represents a halogeno, C.sub.1 -C.sub.4 alkyl, aryl or aralkyl group or a group including at least one heteroatom; and Y represents a group of formula: ##STR2## wherein m.gtoreq.1 (poly-L-glutamates); and the pharmaceutically acceptable salts and esters thereof, which are suitable as anti-cancer agents.

1984-05-08

383

Coumarin derivatives from Gerbera saxatilis.  

PubMed

Phytochemical investigation of Gerbera saxatilis (Astraceae) afforded three new coumarin derivatives 1- 3 and a known coumarin 4. Compounds 1 and 2 represent the first examples of the natural occurrence of the novel polycyclic pyrano[3-2c]coumarin carbon skeleton. The structures of compounds 1- 4 were characterized based on extensive spectroscopic analyses as well as comparison to the spectroscopic data reported. The structures of compounds 1 and 3 were further confirmed by X-ray data analyses. The cytotoxic activity of compounds 1- 4 was evaluated against selected cancer cell lines, including human leukemia cell (HL-60), human hepatoma cell (SMMC-7721), and human cervical carcinoma cell (HeLa) lines. PMID:20669089

Qiang, Yin; Chen, Yan-Jun; Li, Ya; Zhao, Jing; Gao, Kun

2010-07-28

384

Endothelium-derived endothelin-1  

PubMed Central

One year after the revelation by Dr. Furchgott in 1980 that the endothelium was obligatory for acetylcholine to relax isolated arteries, it was clearly shown that the endothelium could also promote contraction. In 1988, Dr. Yanagisawa’s group identified endothelin-1 (ET-1) as the first endothelium-derived contracting factor. The circulating levels of this short (21-amino acid) peptide were quickly determined in humans, and it was reported that, in most cardiovascular diseases, circulating levels of ET-1 were increased, and ET-1 was then tagged as “a bad guy.” The discovery of two receptor subtypes in 1990, ETA and ETB, permitted optimization of the first dual ET-1 receptor antagonist in 1993 by Dr. Clozel’s team, who entered clinical development with bosentan, which was offered to patients with pulmonary arterial hypertension in 2001. The revelation of Dr. Furchgott opened a Pandora’s box with ET-1 as one of the actors. In this brief review, we will discuss the physiological and pathophysiological role of endothelium-derived ET-1 focusing on the regulation of the vascular tone, and as much as possible in humans. The coronary bed will be used as a running example in this review because it is the most susceptible to endothelial dysfunction, but references to the cerebral and renal circulation will also be made. Many of the cardiovascular complications associated with aging and cardiovascular risk factors are initially attributable, at least in part, to endothelial dysfunction, particularly dysregulation of the vascular function associated with an imbalance in the close interdependence of nitric oxide and ET-1.

Thorin, Eric; Webb, David J.

2013-01-01

385

Basic cholane derivatives. XI: Comparison between acid and basic derivatives.  

PubMed

A series of hydroxycholan-24-amines was synthesized; the carboxyl group of starting unconjugated bile acids was transformed into a basic moiety [-NH2, -NHCH3, -N(CH3)2, or -NHCH2C6H5] at C-24. Solubilities, acidities, partition coefficients, and critical micellar concentrations were measured and compared with those of the corresponding bile acids. Because the steroid nucleus in the amines is the same as that in the bile acids, most of the physical-chemical properties of the two compound classes were similar. The amines were more soluble than the corresponding acids; solubilities depended mainly on the number of steroid hydroxyls and, to a lesser extent, on the side chain. Amines are strong bases in water, whereas unconjugated bile acids can be classified as weak acids. N-Benzylamino derivatives have higher log P (P is partition coefficient) values, as a consequence of the bulky hydrophobic substituent; the log P values were almost the same for the amines and the bile acids and depended on the steroid hydroxyls. Amines can self-aggregate at an acidic pH and form cationic micelles; the critical micellar concentrations of amines were of the same order of magnitude as those of bile acids. The introduction of a basic function in the side chain of the cholane moiety increased the antimicrobial activity toward most gram-positive strains. PMID:1403713

Fini, A; Fazio, G; Roda, A; Bellini, A M; Mencini, E; Guarneri, M

1992-07-01

386

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

387

Representations of partial derivatives in thermodynamics  

NASA Astrophysics Data System (ADS)

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.

2012-02-01

388

a Variational Derivation of P  

NASA Astrophysics Data System (ADS)

Multigroup P_{N} theory is a widely-used approximation to multigroup transport theory. However, there are aspects of multigroup P _{N} theory that are not satisfactory, particularly regarding boundary conditions at a boundary having a prescribed incident flux. Historically, P _{N} boundary conditions at such a boundary have been assumed to be in the form given by Marshak or Mark, although Federighi and Pomraning have considered other possibilities for the case of one energy group. In this work we introduce two new variational principles. The first principle, unambiguously leads from a steady-state, first order, slab geometry multigroup transport problem to a multigroup P_{N} problem. The variationally-derived P_{N } problem consists of the conventional multigroup P_{N} equations and variational boundary conditions. At a boundary with a prescribed incident flux, these conditions are new and consistitute a generalization of Pomraning's boundary conditions applied to each energy group. For a vacuum boundary, these conditions reduce the Federighi's boundary condition applied to each energy group. Therefore, we refer to these newly developed P _{N} boundary conditions as the Generalized Federighi-Pomraning (GFP) boundary conditions. The second variational principle introduced in this work leads from a steady-state, even-parity slab geometry, multigroup transport problem to a multigroup, second-order P _{N} problem. This problem consists of the multigroup second-order P_{N } equations and Marshak boundary conditions. We generalize the second-order variational procedure to the three-dimensional geometry and obtain the general geometry multigroup second-order P_{N} equations and the three-dimensional Marshak-like boundary conditions. We also show how the first-order variational principle can be used to derive rigorous boundary conditions for the even-order P_{N}~imations and that these P_{N} approximations can provide accurate numerical results. Finally, a numerical comparison of the Generalized Federighi-Pomraning, Mark, Marshak and (newly developed by Larsen and Pomraning) variational-asymptotic boundary conditions shows that outside the asymptotic limit in which the variational-asymptotic and GFP boundary conditions are always superior, different boundary conditions perform best in different physical situations.

Rulko, Robert Pawel

389

Massive Higher Derivative Gravity Theories  

NASA Astrophysics Data System (ADS)

In this thesis massive higher derivative gravity theories are analyzed in some detail. One-particle scattering amplitude between two covariantly conserved sources mediated by a graviton exchange is found at tree-level in D dimensional (Anti)-de Sitter and flat spacetimes for the most general quadratic curvature theory augmented with the Pauli-Fierz mass term. From the amplitude expression, the Newtonian potential energies are calculated for various cases. Also, from this amplitude and the propagator structure, a three dimensional unitary theory is identified. In the second part of the thesis, the found three dimensional unitary theory is studied in more detail from a canonical point of view. The general higher order action is written in terms of gauge-invariant functions both in flat and de Sitter backgrounds. The analysis is extended by adding static sources, spinning masses and the gravitational Chern-Simons term separately to the theory in the case of flat spacetime. For all cases the microscopic spectrum and the masses are found. In the discussion of curved spacetime, the masses are found in the relativistic and non-relativistic limits. In the Appendix, some useful calculations that are frequently used in the bulk of the thesis are given.

Gullu, Ibrahim

2012-01-01

390

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

391

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

392

Biosynthesis and biotechnological production of serotonin derivatives  

Microsoft Academic Search

Serotonin derivatives belong to a class of phenylpropanoid amides found at low levels in a wide range of plant species. Representative\\u000a serotonin derivatives include feruloylserotonin (FS) and 4-coumaroylserotonin (CS). Since the first identification of serotonin\\u000a derivatives in safflower seeds, their occurrence, biological significance, and pharmacological properties have been reported.\\u000a Recently, serotonin N-hydroxycinnamoyl transferase (SHT), which is responsible for the synthesis

Kiyoon Kang; Sangkyu Park; Young Soon Kim; Sungbeom Lee; Kyoungwhan Back

2009-01-01

393

Method for manufacturing neuraminic acid derivatives  

US Patent & Trademark Office Database

A method for manufacturing neuraminic acid derivatives is provided, also synthetic intermediates of the neuraminic acid derivatives and methods for their manufacture, and neuraminic acid derivatives having high purity. [Means for Solution] A synthetic intermediate compound represented by the formula (7) is provided: ##STR00001## [wherein R.sup.3 represents alkyl; R.sup.4 and R.sup.5 each represents H, alkyl, phenyl, or together represent tetramethylene, pentamethylene, oxo].

2013-06-04

394

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

395

Proceedings of refuse-derived fuel (RDF)  

SciTech Connect

This book contains proceedings of Refuse-Derived Fuel (RDF)-Quality. Standards and Processing. Topics covered include: An Overview of RDF Processing Systems: Current Status, Design Features, and Future Trends. The Impact of Recycling and Pre-Combustion Processing of Municipal Solid Waste on Fuel Properties and Steam Combustion. The Changing Role of Standards in the Marketing of RDF. Refuse Derived Fuel Quality Requirements for Firing in Utility, Industrial or Dedicated Boilers. Refuse-Derived Fuel Moisture Effects on Boiler Performance and Operability. Refuse Derived Fuels: Technology, Processing, Quality and Combustion Experiences.

Saltiel, C. (Florida Univ., Gainesville, FL (United States))

1991-01-01

396

Polystyrene bound oxidovanadium(IV) and dioxidovanadium(V) complexes of histamine derived ligand for the oxidation of methyl phenyl sulfide, diphenyl sulfide and benzoin.  

PubMed

Ligand Hsal-his (I) derived from salicylaldehyde and histamine has been covalently bound to chloromethylated polystyrene cross-linked with 5% divinylbenzene. Upon treatment with [VO(acac)(2)] in DMF, the polystyrene-bound ligand (abbreviated as PS-Hsal-his, II) gave the stable polystyrene-bound oxidovanadium(iv) complex PS-[V(IV)O(sal-his)(acac)] , which upon oxidation yielded the dioxidovanadium(v) PS-[V(V)O(2)(sal-his)] complex. The corresponding non polymer-bound complexes [V(IV)O(sal-his)(acac)] and [V(V)O(2)(sal-his)] have also been obtained. These complexes have been characterised by IR, electronic, (51)V NMR and EPR spectral studies, and thermal as well as scanning electron micrograph studies. Complexes and have been used as a catalyst for the oxidation of methyl phenyl sulfide, diphenyl sulfide and benzoin with 30% H(2)O(2) as oxidant. Under the optimised reaction conditions, a maximum of 93.8% conversion of methyl phenyl sulfide with 63.7% selectivity towards methyl phenyl sulfoxide and 36.3% towards methyl phenyl sulfone has been achieved in 2 h with 2 . Under similar conditions, diphenyl sulfide gave 83.4% conversion where selectivity of reaction products varied in the order: diphenyl sulfoxide (71.8%) > diphenyl sulfone (28.2%). A maximum of 91.2% conversion of benzoin has been achieved within 6 h, and the selectivities of reaction products are: methylbenzoate (37.0%) > benzil (30.5%) > benzaldehyde-dimethylacetal (22.5%) > benzoic acid (8.1%). The PS-bound complex, 1 exhibits very comparable catalytic potential. These polymer-anchored heterogeneous catalysts do not leach during catalytic action, are recyclable and show higher catalytic activity and turnover frequency than the corresponding non polymer-bound complexes. EPR and (51)V NMR spectroscopy was used to characterise methanolic solutions of 3 and 4 and to identify species formed upon addition of H(2)O(2) and/or acid and/or methyl phenyl sulfide. PMID:19274297

Maurya, Mannar R; Arya, Aarti; Kumar, Amit; Pessoa, João Costa

2009-02-03

397

Asymmetric syntheses of pipecolic acid and derivatives  

Microsoft Academic Search

Summary Results in the field of asymmetric synthesis of pipecolic acid derivatives are reviewed. Three sections describe the asymmetric syntheses of the title compounds (i) from the chiral pool (a-amino acids or carbohydrates) (ii) using a chiral auxiliary either derived from terpenes,a-amino acids, tartaric acid, an amine orß-amino alcohols (iii) by means of asymmetric catalysis.

François Couty

1999-01-01

398

Benzimidazole derivatives as potential anticancer agents.  

PubMed

Benzimidazole ring system is found in many bioactive heterocyclic compounds because of their diverse biological and clinical applications. Furthermore, benzimidazole derivatives are structural isosters of naturally occurring nucleotides, thus they can interact with biological macromolecules such as proteins, enzymes and receptors. This review discusses the benzimidazole derivatives which possess anticancer activity of medicinal efficacy. PMID:23190032

El Rashedy, Ahmed A; Aboul-Enein, Hassan Y

2013-03-01

399

Analysis of Blackbody Radiation with Derivative Spectroscopy.  

ERIC Educational Resources Information Center

Describes an undergraduate experiment which uses derivative spectroscopy to investigate the validity of the Planck function appearing in the blackbody radiation law. These measurements allow a critical examination of this function and also serve as an introduction to derivative spectroscopy techniques. (Author/HM)

Dusek, J.; And Others

1980-01-01

400

Smoothing Splines: Regression, Derivatives and Deconvolution  

Microsoft Academic Search

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 integral equation. These results are derived by developing a Fourier representation for a

John Rice; Murray Rosenblatt

1983-01-01

401

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

402

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

403

Derivative Markets' Impact on Colombian Monetary Policy  

Microsoft Academic Search

Derivatives are contingent claims that complete financial markets. Their use allow agents and firms to ameliorate the impact over con- sumption, production and investment given a change in relative prices induced by an active monetary policy. In this sense, derivatives gene- rate in some cases a loss in the effectiveness of the traditional monetary transmission channels in the short run,

Esteban Gómez; Diego Vásquez; Camilo Zea

404

Deriving Mode Invariants from SCR Specifications  

Microsoft Academic Search

This paper introduces a formal analysis method to derive modeclass invariants from software cost reduction (SCR) specifications. SCR specifications can be used to specify event-driven systems. Mode invariants in SCR specifications are used to capture safety features that must be ensured during software development. This new method derives mode invariants from well-defined, consistent SCR specifications by transforming an SCR mode

Zhenyi Jin

1996-01-01

405

Inter-relations among flutter derivatives  

Microsoft Academic Search

The interrelations and the approximate equivalences (or dependences) among the flutter derivatives of a low-speed airfoil are analytically described. Using the experimentally obtained flutter derivatives of three different bridge deck sections, the possible validity of the analogous relations for bridges is investigated and discussed.

R. H. Scanlan; N. P. Jones; L. Singh

1997-01-01

406

Comparative analysis of accounting treatments for derivatives  

Microsoft Academic Search

This paper provides educators with a classroom example or a self-study tutorial to teach Statement of Financial Accounting Standards No. 133 (FAS 133), Accounting for Derivative Instruments and Hedging Activities. The example can be used in courses such as intermediate or advanced accounting that discuss derivative instruments or investments topics or in a training program that focuses on implementing FAS

Angela L. J. Hwang

2002-01-01

407

Polymyxin derivatives: a patent evaluation (WO2012168820).  

PubMed

The patent application WO201268820 claims a new class of polymyxin derivatives with potent antibacterial activity, especially toward Gram-negative pathogens. Compared to parent polymyxin B (PMB), the new derivatives have more potent antibacterial activity, as well as reduced cytotoxicity against human renal cells. PMID:23806121

Wu, Haifan; Teng, Peng; Niu, Youhong; Li, Qi; Cai, Jianfeng

2013-06-28

408

1 H NMR, IR and UV\\/VIS Spectroscopic Studies of Some Schiff Bases Derived From 2-Aminobenzothiazole and 2Amino3-hydroxypyridine  

Microsoft Academic Search

By condensing 2-aminobenzothiazole with 2-hydroxy-1-naphthaldehyde, 2-hydroxybenzaldehyde, 4-methoxybenzaldehyde, 4-hydroxybenzal-dehyde, benzaldehyde and 4-dimethylaminobenzaldehyde, and five Schiff bases Ia-Ie are prepared. Also, two Schiff bases IIa and IIb are prepared by condensation of 2-amino-3-hydroxypyridine with 2-hydroxy-1-naphthaldehyde and 2-hydroxybenzaldehyde. The 1H NMR, IR and UV\\/Vis spectra of these seven Schiff bases are investigated. The signals of the 1 HN MR spectra as well as

Raafat M. Issa; Abdalla M. Khedr; Helen Rizk

409

Biological Analysis of Progressive Toxicity of Shale-Derived versus Petroleum-Derived Fuels in Rats.  

National Technical Information Service (NTIS)

The administration of petroleum-derived and shale-derived JP5 (Jet Propulsion No.5) to rats resulted in hepatocellular damage characterized by periportal fatty change, increase in binucleated cells, mitotic figures, and cellular necrosis. Elevated levels ...

W. J. Mehm C. L. Feser

1984-01-01

410

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

411

Perhydroindan Derivatives. Ix. The Diels-Alder Reaction with 7-Methylindene Derivatives.  

National Technical Information Service (NTIS)

1,2-Dicarbomethyoxy-7-methylindene has been synthesized. The Diels-Alder reaction of this indene derivative with butadiene has been found to occur without migration of the carbon-carbon double bond to form the tetrahydrofluorene derivative. (Author)

H. O. House F. J. Sauter

1967-01-01

412

On Relations between the Derivative and the Two-Dimensional Directional Derivatives of a Quaternionic Function  

NASA Astrophysics Data System (ADS)

There is established the concept of two-dimensional directional derivative of a quaternionic function, which is related with the notion of Cullen regularity considered in detail by Gentili and Struppa. There are presented some relations between the notion of quaternionic derivative and two-dimensional directional derivatives.

Luna-Elizarrarás, M. E.; Macías-Cedeño, M. A.; Shapiro, M.

2007-09-01

413

ADIFOR: Fortran source translation for efficient derivatives  

SciTech Connect

The numerical methods employed in the solution of many scientific computing problems require the computation of derivatives of a function f: R{sup n} {yields} R{sup m}. Both the accuracy and the computational requirements of the derivative computation are usually of critical importance for the robustness and speed of the numerical method. ADIFOR (Automatic Differentiation In FORtran) is a source translation tool implemented using the data abstractions and program analysis capabilities of the ParaScope Parallel Programming Environment. ADIFOR accepts arbitrary Fortran-77 code defining the computation of a function and writes portable Fortran-77 code for the computation of its derivatives. In contrast to previous approaches, ADIFOR views automatic differentiation as a process of source translation that exploits computational context to reduce the cost of derivative computations. Experimental results show that ADIFOR can handle real-life codes, providing exact derivatives with a running time that is competitive with the standard divided-difference approximations of derivatives and which may perform orders of magnitude faster than divided-differences in cases. The computational scientist using ADIFOR is freed from worrying about the accurate and efficient computation of derivatives, even for complicated functions,'' and hence, is able to concentrate on the more important issues of algorithm design or system modeling. 35 refs.

Bischof, C.; Corliss, G.; Griewank, A.; Hovland, P. (Argonne National Lab., IL (United States)); Carle, A. (Rice Univ., Houston, TX (United States). Center for Research on Parallel Computation)

1992-01-01

414

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

415

Four new bibenzyl derivatives from Dendrobium candidum.  

PubMed

Four new bibenzyl derivatives, namely, dendrocandins F-I (1-4), were isolated from the stems of Dendrobium candidum. Their structures were elucidated by the analysis of spectroscopic data. Dendrocandins F and G represent the fourth and fifth example of bisbibenzyl derivates with a dibenzopyran ring between two units, respectively. Dendrocandin H represents the first example of a bibenzyl derivative formed by a bibenzyl and a 1,4-phenanthraquinone unit via a dibenzopyran ring. Compounds 1-4 were examined for antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay. PMID:19721264

Li, Yan; Wang, Chun-Lan; Wang, Ya-Jun; Wang, Fang-Fei; Guo, Shun-Xing; Yang, Jun-Shan; Xiao, Pei-Gen

2009-09-01

416

[Research progress of chromanone derivatives from Calophyllum].  

PubMed

Calophyllum plants have great pharmaceutical value. Some species of this genus are used in folk medicine to treat and cure diseases, such as toothache, rheumatism, diarrhea, chronic ulcers, skin infections, and wounds. The genus is known to be rich in chromanone derivatives, and some of these compounds have antiviral, antifungal, antibacterial, cytotoxic, and other activities. In order to come to a more complete understanding of chromanone derivatives and gain new bioactive constituents from Calophyllum, chemical structures, pharmacological activities, and biogenesis of chromanone derivatives from Calophyllum have been discussed in this review. PMID:21842632

Wang, Huan; Wang, Yuehu; Li, Juan; Chen, Lijuan

2011-05-01

417

An endothelial cell-derived growth factor  

Microsoft Academic Search

Cell-free plasma-derived serum(PDS) isdeficient intheplatelet-derived growth factorand willnotsupportthegrowthof3T3 cells, fibroblasts, orsmoothmuscle cells .However,when PDS-containingmedium ispreincubatedwithendothelial cells, themedium becomesmodifiedsothatitwillsupportgrowth.The activity producedby theendothelial cellsresults from a polypeptideof10,000to30,000 daltonswhich hasseveralfeaturesthatdifferfrom thoseoftheplatelet-derived growthfactor, includingheatinstability and lackofadsorption toCM Sephadex. Growth ofnontransformed cellstrainsin culture requires one or more exogenous growth factors. The availabilityofthese polypeptides appears to determine the extent ofgrowth, and account, at leastin part, for

CORINNE GAJDUSEK; PAUL DICORLETO; RUSSELL ROSS; STEPHEN M. SCHWARTZ

1980-01-01

418

Derived Categories and Zero-Brane Stability  

SciTech Connect

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 Douglas. We then argue that any 0-brane on any Calabi-Yau threefold must become unstable along some path in the Kahler moduli space. As a byproduct of this analysis we see how the derived category can be invariant under a birational transformation.

Lawrence, Albion

2001-07-25

419

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

420

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

421

32 CFR 2001.22 - Derivative classification.  

Code of Federal Regulations, 2013 CFR

...described in E.O. 12951, âRelease of Imagery Acquired by Space-Based National Intelligence Reconnaissance Systems,â the derivative...as prescribed by the Director of National Intelligence. (4) When determining the most...

2013-07-01

422

32 CFR 2001.22 - Derivative classification.  

Code of Federal Regulations, 2010 CFR

...described in E.O. 12951, âRelease of Imagery Acquired by Space-Based National Intelligence Reconnaissance Systems,â the derivative...as prescribed by the Director of National Intelligence. (4) When determining the most...

2010-07-01

423

Peanut-Derived Products Used as Ingredients  

Center for Food Safety and Applied Nutrition (CFSAN)

... work with their suppliers to ensure that all peanut-derived products used as ingredients or sold as food are not subject to an on-going product recall ... More results from www.fda.gov/food/guidanceregulation/retailfoodprotection

424

Cellulose Derivatives for Water Repellent Properties  

Technology Transfer Automated Retrieval System (TEKTRAN)

Synthesis and structural characterizations of nitro-benzyl cellulose, amino-benzyl cellulose and pentafluoro –benzyl cellulose were carried out. Cellulose derivatives were synthesized by etherification process in lithium chloride/N,N-dimethylacetamide homogeneous solution. Nitrobenzylation was effec...

425

Moment Systems Derived from Relativistic Kinetic Equations  

NASA Astrophysics Data System (ADS)

In this paper, we are interested in the derivation of macroscopic equations from kinetic ones using a moment method in a relativistic framework. More precisely, we establish the general form of moments that are compatible with the Lorentz invariance and derive a hierarchy of relativistic moment systems from a Boltzmann kinetic equation. The proof is based on the representation theory of Lie algebras. We then extend this derivation to the classical case and general families of moments that obey the Galilean invariance are also constructed. It is remarkable that the set of formal classical limits of the so-obtained relativistic moment systems is not identical to the set of classical moments quoted in Ref. 21 and one could use a new physically relevant criterion to derive suitable moment systems in the classical case. Finally, the ultra-relativistic limit is considered.

Bagland, Véronique; Degond, Pierre; Lemou, Mohammed

2006-11-01

426

Embryonic stem cell derivation from human embryos.  

PubMed

Human embryonic stem cells (hESCs) are self-renewing, pluripotent cells that serve as a valuable research tool and hold promise for use in regenerative medicine. Most hESC lines are derived from cryopreserved human embryos that were created during in vitro fertilization (IVF) and are in excess of clinical need. Embryos that are discarded during the IVF procedure are also a viable source of hESCs. hESCs can be derived from pre-blastocyst embryos and even from single blastomeres. However, hESC line derivation efficiency is greatest using embryos that have reached the blastocyst stage. This chapter describes a protocol for the derivation of pluripotent stem cell lines from human embryos. PMID:21822865

Lerou, Paul

2011-01-01

427

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

428

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

429

Derivation of Relativistic Effects in Satellite Tracking.  

National Technical Information Service (NTIS)

Starting with the Schwarzschild solution to Einstein's field equations, the equations for relativistic corrections to satellite tracking are derived. Included are corrections for range from satellite to earth station, range from satellite to satellite, an...

L. R. Gibson

1983-01-01

430

Hydrothermal Syntheses of Some Derivatives of Tetraazatriphenylene  

Microsoft Academic Search

Some derivatives of tetraazatriphenylene can be synthesized readily by a hydrothermal synthetic method. Compared with the traditional technique, this method is effective and simple process, and much high yields of products with higher purity can be harvested.

Guangbo Che; Wenlian Li; Zhiguo Kong; Zisheng Su; Bei Chu; Bin Li; Zhiqiang Zhang; Zhizhi Hu; Haijun Chi

2006-01-01

431

12 CFR 163.172 - Financial derivatives.  

Code of Federal Regulations, 2013 CFR

12 Banks and Banking 1 2013-01-01 2013-01-01 false Financial derivatives. 163.172 Section 163.172 Banks and Banking COMPTROLLER OF THE CURRENCY...ASSOCIATIONS-OPERATIONS Financial Management Policies §...

2013-01-01

432

12 CFR 563.172 - Financial derivatives.  

Code of Federal Regulations, 2013 CFR

12 Banks and Banking 6 2013-01-01 2012-01-01 true Financial derivatives. 563.172 Section 563.172 Banks and Banking OFFICE OF THRIFT SUPERVISION...ASSOCIATIONS-OPERATIONS Financial Management Policies §...

2013-01-01

433

Diarylbenzopyran derivatives as cyclooxygenase-2 inhibitors  

US Patent & Trademark Office Database

The diarylbenzopyran derivatives represented by formula I, and the pharmaceutically acceptable salts thereof, are disclosed. The composition comprising the compound of formula I, or a pharmaceutically acceptable salt thereof, shows an excellent selective inhibition of cyclooxygenase-2. ##STR1##

2002-01-22

434

Inhibition of MXR transport by acridine derivatives  

US Patent & Trademark Office Database

This invention provides methods that are useful for inhibiting a MXR transporter in a cell overexpressing a MXR gene but not overexpressing a Pgp gene by contacting the cell with an acridine derivative. The invention also provides for a method of treating a mammal suffering from a cancer, which overexpressing a MXR gene but not overexpress a Pgp gene, by the co-administration of a chemotherapeutic and an acridine derivative.

2003-02-18

435

A New Derivation of Jeffery's Equation  

NASA Astrophysics Data System (ADS)

In this article, we present a modern derivation of Jeffery’s equation for the motion of a small rigid body immersed in a Navier Stokes flow, using methods of asymptotic analysis. While Jeffery’s result represents the leading order equations of a singularly perturbed flow problem involving ellipsoidal bodies, our formulation is for bodies of general shape and we also derive the equations of the next relevant order.

Junk, Michael; Illner, Reinhard

2007-12-01

436

Molluscicidal and trypanocidal activities of lapachol derivatives.  

PubMed

The activity of the potassium salt of lapachol against the snail Biomphalaria glabrata and its egg masses was tested. The obtained IC50 values (2.70 ppm and 1.43 ppm, respectively) are indicative of a strong activity. Lapachol derivatives were also assayed against infective trypomastigote blood forms of T. cruzi and the triacetoxy derivative of reduced lapachol showed relevant trypanocidal activity, killing 95.7% of the parasites at the concentration of 42 microg/mL. PMID:11270734

Santos, A F; Ferraz, P A; de Abreu, F C; Chiari, E; Goulart, M O; Sant'Ana, A E

2001-02-01

437

Antioxidant activity of chlorophylls and their derivatives  

Microsoft Academic Search

The antioxidant activity of six natural isolated chlorophyll derivatives and Cu-chlorophyllin was investigated by measuring their protective action against lipid oxidation. For this, the ?-carotene bleaching method and the stable radical 2,2-diphenyl-1-picryldrazyl (DPPH) scavenging assay were employed. The results obtained by the ?-carotene bleaching method showed that all chlorophyll derivatives presented a dose-dependent response. Pheophorbide b and pheophytin b were

Ursula M. Lanfer-Marquez; Rosa M. C. Barros; Patricia Sinnecker

2005-01-01

438

Duality completion of higher derivative corrections  

NASA Astrophysics Data System (ADS)

We present a new method for completing higher derivative corrections for theories that exhibit duality symmetries under reduction. This proposal is based on the observation that duality symmetry in the reduced theory highly constrains the form of the unreduced theory. We apply this idea to closed bosonic string theory and complete the Riemann squared term to simply derive the known full tree-level effective action to order ?'.

Godazgar, Hadi; Godazgar, Mahdi

2013-09-01

439

Defining DTG derivations to get semantic graphs  

Microsoft Academic Search

this paper is to find a formalism of theTAG family, where the derivation controller can beinterpreted as a semantic dependency graph, in thesense of Meaning-Text Theory (ZM67; M88).In a previous paper (CK98), we study thisinterpretation of the derivation tree (DT) in the caseof standard TAG. We prove that, in the general case,if the predicate-argument cooccurence principle

Marie-Hélène Candito; Sylvain Kahane

1998-01-01

440

Antimalarial Activities of Dermaseptin S4 Derivatives  

Microsoft Academic Search

The hemolytic antimicrobial peptide dermaseptin S4 was recently shown to exert antimalarial activity. In this study, we attempted to understand the underlying mechanism(s) and identify derivatives with improved antimalarial activity. A number of dermaseptin S4 derivatives inhibited parasite growth with a 50% inhibitory concentration (IC50) in the micromolar range. Among these, the substituted S4 analog K4K20-S4 was the most potent

MIRIAM KRUGLIAK; RINA FEDER; VADIM Y. ZOLOTAREV; LEONID GAIDUKOV; ARIE DAGAN; HAGAI GINSBURG; AMRAM MOR

2000-01-01

441

Leishmanicidal activity of new megazol derivatives.  

PubMed

A series of thirteen new megazol derivatives, designed exploring the molecular hybridization approach between megazol (3) and heterocombretastatins (2), was synthesized. These new compounds were tested for in vitro antiparasitic activity upon axenic amastigotes of Leishmania donovani. Biological results led us to identify a new potent megazol derivative (4g), which presents an IC(50) = 0.081microg/mL, more active tham the reference drug miltefosine (IC(50) = 0.131microg/mL). PMID:19689398

Riente, R R; Souza, V P; Carvalho, S A; Kaiser, M; Brun, R; da Silva, E F

2009-07-01

442

Preferential maternal derivation in inv dup(15)  

Microsoft Academic Search

Eight patients are reported with a de nov extra inverted duplicated chromosome 15. The abnormal chromosome was considered to be the same in all cases, but its precise delineation remained uncertain and was defined as either 15qter?15q12::15q12?15pter or 15pter?15q11::15q13?15pter. Analysis with various techniques of the satellite regions of the bisatellited chromosomes demonstrated maternal derivation in six and paternal derivation in

Paola Maraschio; Orsetta Zuffardi; Franca Bernardi; M. Bozzola; C. De Paoli; Christa Fonatsch; Sibylle D. Flatz; Loretta Ghersini; G. Gimelli; M. Loi; Renata Lorini; Diletta Peretti; Lisa Poloni; Daniela Tonetti; Roberta Vanni; G. Zamboni

1981-01-01

443

Thermal conductivity of pitch-derived fibres  

Microsoft Academic Search

The temperature variation of the thermal conductivity of pitch-derived carbon fibres measured from 3 to 300K is reported and discussed. The results are compared with those previously obtained on benzene-derived fibres (BDF) and with the room-temperature thermal conductivity of PAN-based carbon fibres, the GY70. The data confirm that the structure of pitch fibres is less perfect than that of BDF.

B. Nysten; L. Piraux; J.-P. Issi

1985-01-01

444

Stabilization of biomass-derived pyrolysis oils  

Microsoft Academic Search

BACKGROUND:Biomassistheonlyrenewablefeedstockcontainingcarbon,andthereforetheonlyalternativetofossil-derived crude oil derivatives. However, the main problems concerning the application of biomass for biofuels and bio-based chemicals are related to transport and handling, the limited scale of the conversion process and the competition with the food industry. Toovercome suchproblems,anintegralprocessing routefortheconversionof(non-feed)biomass(residues)totransportation fuels is proposed. It includes a pretreatment process by fast pyrolysis, followed by upgrading to produce a crude-oil-like product,

A. Oasmaa; J. Wildschut; A. R. Ardiyanti; R. H. Venderbosch; H. J. Heeres

2010-01-01

445

Myeloid derived suppressor cells in transplantation.  

PubMed

Myeloid derived suppressor cells (MDSC) are a heterogeneous population of hematopoietic derived cell precursors that can suppress immune responses in a variety of inflammatory settings. Here we review recent studies detailing expansion of phenotypically and functionally disparate MDSC. Findings related to MDSC accumulation, activation, and mechanisms utilized in immune suppression are presented. Further, we discuss recent reports that suggest MDSC are expanded during transplantation and that modulation of MDSC can participate in preventing graft rejection. PMID:21802931

Lees, Jason R; Azimzadeh, Agnes M; Bromberg, Jonathan S

2011-07-28

446

Derived versus full name brand extensions  

Microsoft Academic Search

Most brand extension studies follow the assumption that brand extensions use the full original parent brand name (e.g., Oral-B tooth brush may extend to Oral-B dental floss). However, some companies use derived brand names in their brand extension strategies (e.g. Nestea Iced Tea). This study explores the advantages and disadvantages of derived brand extensions compared to full name extensions. The

Sergio Olavarrieta; Eduardo Torres; Arturo Vásquez-Parraga; Cristóbal Barra

2009-01-01

447

Four new citrinin derivatives from a marine-derived Penicillium sp. fungal strain.  

PubMed

Four new citrinin derivatives, including two citrinin dimers and two citrinin monomer derivatives, were isolated and identified from a marine-derived fungal strain Penicillium sp. ML226 along with six known related compounds. Their structures were elucidated by spectroscopic and chemical methods. The new compounds showed modest cytotoxic activity against HepG-2 cell line and weak antimicrobial activity against Staphylococcus aureus. PMID:23681057

Wang, Mei Ling; Lu, Chun Hua; Xu, Qing Yan; Song, Si Yang; Hu, Zhi Yu; Zheng, Zhong Hui

2013-05-16

448

Novel benzimidazole derivatives as expected anticancer agents.  

PubMed

A series of 1-(1H-benzimidazol-2-yl)-3-(substituted)-2-propen-1-one and its 1-methyl analogues 2c-h were synthesized and cyclized with different reagents such as ethyl cyanoacetate, thiourea, hydroxylamine hydrochloride, guanidinium sulfate, methylhydrazine, phenylhydrazine and/or hydrogen peroxide in different reactions to produce pyridones 3a,b, pyrimidinethione 4a,b, isoxazole 5a,b, aminopyrimidine 6a,b, pyrazoline 7i-k and epoxy derivative 8, respectively. Acetohydrazide 10 reacted with formic acid, acetic anhydride, carbon disulfide and/or thiosemicarbazide to yield compounds 11-19. Also compound 21a,b was condensed with different monosaccharides to yield the corresponding N-glycoside Schiff's bases derivatives 22a-h, which upon treatment with acetic anhydride afforded 23a-h derivatives. The anticancer activity of some of the newly synthesized compounds was evaluated against HEPG2 (human liver carcinoma cell line) and PC12 (pheochromocytoma of the rat adrenal medulla) cells. Benzimidazole-2-isoxazole 5a derivative exhibited high potency against HEPG2 and PC12 cells. Benzimidazole chalcones 2c,e, benzimidazole mercaptoacetohydrazide 14 and benzimidazole thiosemicarbazide 15a,b derivatives gave high potency against PC12 cells. PMID:21796934

Nofal, Zienab M; Soliman, Elsyed A; Abd El-Karim, Somaia S; El Zahar, Magdy I; Srour, Aladdin M; Sethumadhavan, Shalini; Maher, Timothy J

449

Derivative expansion of the effective action  

SciTech Connect

This paper describes some methods for calculating derivative terms in the one loop effective action for a quantum field theory. The functional approach and background field method are first used to derive the general form of the one loop determinant. Then the determinant is expanded in powers of derivatives of the background fields. The form of this expansion is described for the simple case of an interacting scalar field, and then for the more complicated problem of a non-abelian gauge field. Finally, the expansion is applied to the task of calculating Higgs mass dependent effects in the Glashow-Weinberg-Salam model, and all terms which grow with the Higgs mass M/sub H/ are found in the one loop approximation. The result of this calculation is used to find the dependence of the gauge boson mass ratio rho on M/sub H/, and also to estimate the size of corrections to W and Z scattering theorems.

Cheyette, O.

1987-04-01

450

Photochemistry of riboflavin derivatives in methanolic solutions.  

PubMed

Light-induced degradation of the riboflavin derivatives is reported, including 5-deaza-riboflavin, iso-6,7-riboflavin, 3-methyl-tetra-acetyl-riboflavin (3MeTARF), and 3-benzyl-lumiflavin. The studied compounds undergo photolytic processes with considerable quantum yields in methanolic solutions (? ? 10(-3)-10(-4) mol einst(-1)). Photolysis in anaerobic conditions is more efficient than that in the presence of oxygen. Experiments show that triplet excited state of flavin molecules is involved in the reactions. The main photoproducts are the respective alloxazinic and isoalloxazinic derivatives of the substrates. 3MeTARF reveals higher photostability than riboflavin. The values of photodegradation quantum yields were estimated for the four studied derivatives. PMID:22217187

Insi?ska-Rak, Ma?gorzata; Golczak, Anna; Sikorski, Marek

2012-01-20

451

A thermodynamic derivation of the reciprocal relations.  

PubMed

Starting with the continuity and Smoluchowski equations, we write the mass flux for a system out of equilibrium in terms of the physicochemical potential ?(g). ?(g) is a coarse-grained analog of the chemical potential in the presence of forces that drive the system out of equilibrium. The expression for flux in terms of ?(g) allows for a macroscopic derivation of the Onsager reciprocal relations for the case of transport by diffusion and drift in single or multi-component systems, without recourse to microscopic fluctuations or equations of motion. Transport coefficients for any time reversal-invariant properties now are expressed in terms of only partial molar derivatives and mobilities (diffusion coefficients). The thermodynamic derivation cannot treat time reversal. PMID:23556731

Kocherginsky, N; Gruebele, M

2013-03-28

452

Understanding, Deriving, and Computing Buffer Capacity  

NASA Astrophysics Data System (ADS)

The concept of buffer capacity appears in varied disciplines, including bio-, geo-, analytical, and environmental chemistry, physiology, medicine, dentistry, and agriculture. Unfortunately, however, derivation and systematic calculation of buffer capacity is a topic that seems to be neglected in the undergraduate analytical chemistry curriculum. In this work, we give an account of the development of the buffer capacity concept and derive the buffer capacity contribution equations for buffer systems containing mono-, di-, and triprotic weak acids (and their conjugate bases) and aluminum(III), which undergoes hydrolysis. A brief review of pH is provided because pH is involved in applying buffer capacity to the real world. In addition, we discuss evaluation of the equations, numerical approximation of buffer capacity when an analytic solution is not derived, and the mathematical properties of the buffer capacity expressions.

Urbansky, Edward T.; Schock, Michael R.

2000-12-01

453

Immunosuppressive decalin derivatives from red yeast rice.  

PubMed

Five new decalin derivatives (1-5), together with two known compounds (6 and 7), were isolated from the ethyl acetate extract of red yeast rice. Their structures were elucidated by means of NMR and mass spectroscopic analyses. Monascusic lactone A (1) is the first reported naturally occurring decalin derivative possessing a spiro lactone at the C-1 position. The immunosuppressive effects of all these isolates (1-7) on human T cell proliferation were investigated, and all, especially monascusic acids B (2), C (3), D (4), and A (6) and heptaketide (7), suppressed human T cell proliferation in a dose-dependent manner from 10 to 100 ?M. This is the first report on the immunosuppressive activity of decalin derivatives. PMID:22394155

Zhu, Lin; Lu, Jing-Guang; Li, Ting; Zhu, Guo-Yuan; Han, Quan-Bin; Hsiao, Wen-Luan; Liu, Liang; Jiang, Zhi-Hong

2012-03-06

454

Catalytic hydrotreating of biomass-derived oils  

SciTech Connect

A variety of biomass-derived oils have been upgraded by catalytic hydrotreating in a 1-liter reactor system. High yields of high quality gasoline (C/sub 5/-225/sup 0/C boiling range) can be produced from biomass-derived oils, however, low space velocities (long residence times) are required. At high space velocities a low oxygen, highly aromatic crude oil is produced. Cracking and hydrogenation of the higher molecular weight components are the rate limiting steps in upgrading biomass-derived oils. Catalyst development should be directed at these reactions. The TR7 oil is superior to TR12 and both are much superior to pyrolysis oils as feedstocks for catalytic hydrotreating to produce hydrocarbon fuels. Pyrolysis oils can be upgraded by catalytic hydrotreating; however, a catalytic pretreatment step is required. Residual sodium catalyst needs to be removed from liquefaction products to prevent rapid catalyst fouling.

Baker, E.G.; Elliott, D.C.

1986-10-01

455

A Derivation of Modified Newtonian Dynamics  

NASA Astrophysics Data System (ADS)

Modified Newtonian Dynamics (MOND) is a possible solution for the missing mass problem in galactic dynamics; its predictions are in good agreement with observations in the limit of weak accelerations. However, MOND does not derive from a physical mechanism and does not make predictions on the transitional regime from Newtonian to modified dynamics; rather, empirical transition functions have to be constructed from the boundary conditions and comparisons with observations. I compare the formalism of classical MOND to the scaling law derived from a toy model of gravity based on virtual massive gravitons (the ``graviton picture'') which I proposed recently. I conclude that MOND naturally derives from the ``graviton picture'' at least for the case of non-relativistic, highly symmetric dynamical systems. This suggests that -- to first order -- the ``graviton picture'' indeed provides a valid candidate for the physical mechanism behind MOND and gravity on galactic scales in general.

Trippe, Sascha

2013-04-01

456

Derivation of wildlife values for mercury.  

PubMed

A procedure has been developed to estimate surface water concentrations of toxicants ("wildlife values") that will protect the viability of wildlife populations associated with aquatic resources. This procedure was designed primarily to protect piscivorous birds and mammals from compounds that bioaccumulate in fish and was used in the Great Lakes Water Quality Initiative (GLI) to calculate wildlife values (WV) for mercury, DDT/DDE, total polychlorinated biphenyls (PCBs), and 2,3,7,8-tetrachlorodibenzodioxin (TCDD). Published in 1995, and expressed as total mercury in unfiltered water, the final wildlife value (WVf) for mercury derived in the GLI was 1300 pg Hg/L. This value was selected as the wildlife criterion (WC) for mercury in the Great Lakes basin. A second WVf for mercury was derived in 1997 as part of a Congressionally mandated report on airborne mercury emissions. These calculations were based upon mercury speciation data that were largely unavailable when the GLI was developed. Important features of the WVf in the Report to Congress include its calculation on a dissolved methylmercury basis and a reliance on field data to estimate fish bioaccumulation factors. Calculated as methylmercury in filtered water, the WVf derived in the report is 50 pg Hg/L (equivalent to 54 pg MeHg/L). A comparison of WV in the GLI and the Report to Congress requires that average values be specified for mercury speciation in natural systems. Based on this information, the WVf given in the report corresponds to a value of 910 pg Hg/L, as total mercury in unfiltered water, or about 70% of the WVf derived in the GLI. In this article we describe the algorithm used to derive WV in the GLI and the Report to Congress and review its application to mercury. Scientific uncertainties in deriving WV, particularly as they apply to mercury, are critically examined. PMID:10596301

Nichols, J; Bradbury, S; Swartout, J

457

Transplants of blood-derived hematopoietic cells.  

PubMed

Increasing numbers of transplants, particularly autotransplants, are performed using blood-derived cells. Most subjects have leukemia but others have solid tumors or even genetic disorders. Despite this expanding data base, several important issues are unresolved. Can blood-derived cells reconstitute short-term hematopoiesis? Here, the answer is likely yes, although this is not yet proven. Studies using genetically marked cells should resolve this issue. Next, can blood-derived cells reconstitute long-term hematopoiesis? Here, the answer is unknown, but it would not be surprising were this not so. However, since most (if not all) high-dose chemotherapy and radiation treatments do not completely eradicate endogenous hematopoietic stem cells, reconstitution of long-term hematopoiesis from the graft may not be necessary for blood-derived grafts to be useful clinically. Another unresolved area is whether blood-derived grafts have a lower likelihood of tumor recurrence because of a lower probability of tumor contamination (qualitative or quantitative) or because of a different cellular composition of the graft. This issue is only answerable in controlled trials. Most data suggest that recurrence rate would not be higher than bone marrow-derived grafts. Whether it is lower is unknown. Analysis of this point is confounded by the fact that most (perhaps all) relapses that occur post-transplant using current conditioning schedules are explicable by residual leukemia in the recipient. Thus, tumor contamination of the graft is not presently an operationally important issue. There are some recent developments in this area. One is the use of umbilical cord blood cells to reconstitute hematopoiesis in a child with Fanconi anemia. Additional data are needed to evaluate this approach.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2180517

Gale, R P; Butturini, A

1990-01-01

458

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

459

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

460

Caffeic acid derivatives from Eupatorium perfoliatum L.  

PubMed

From the ethyl acetate soluble fraction of a methanol/water extract of the herb Eupatorium perfoliatum L. (Asteraceae) six caffeic acid derivatives have been isolated and identified by 1D- and 2D-NMR spectroscopic data. Besides the common quinic acid derivatives 5-caffeoylquinic acid (chlorogenic acid), 3-caffeoylquinic acid (neochlorogenic acid) and 3,5-dicaffeoylquinic acid, three up to now unknown depsides of caffeic acid with glucaric acid have been isolated: 2,5-dicaffeoylglucaric acid, 3,4-dicaffeoylglucaric acid, and 2,4- or 3,5-dicaffeoylglucaric acid. PMID:19104484

Maas, Mareike; Petereit, Frank; Hensel, Andreas

2008-12-23