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Sample records for amidines

  1. Synthesis of Calcium(II) Amidinate Precursors for Atomic Layer Deposition through a Redox Reaction between Calcium and Amidines.

    Science.gov (United States)

    Kim, Sang Bok; Yang, Chuanxi; Powers, Tamara; Davis, Luke M; Lou, Xiabing; Gordon, Roy G

    2016-08-22

    We have prepared two new Ca(II) amidinates, which comprise a new class of ALD precursors. The syntheses proceed by a direct reaction between Ca metal and the amidine ligands in the presence of ammonia. Bis(N,N'-diisopropylformamidinato)calcium(II) (1) and bis(N,N'-diisopropylacetamidinato)calcium(II) (2) adopt dimeric structures in solution and in the solid state. X-ray crystallography revealed asymmetry in one of the bridging ligands to afford the structure [(η(2) -L)Ca(μ-η(2) :η(2) -L)(μ-η(2) :η(1) -L)Ca(η(2) -L)]. These amidinate complexes showed unprecedentedly high volatility as compared to the widely employed and commercially available Ca(II) precursor, [Ca3 (tmhd)6 ]. In CaS ALD with 1 and H2 S, the ALD window was approximately two times wider and lower in temperature by about 150 °C than previously reported with [Ca3 (tmhd)6 ] and H2 S. Complexes 1 and 2, with their excellent volatility and thermal stability (up to at least 350 °C), are the first homoleptic Ca(II) amidinates suitable for use as ALD precursors. PMID:27351794

  2. Synthesis of Calcium(II) Amidinate Precursors for Atomic Layer Deposition through a Redox Reaction between Calcium and Amidines.

    Science.gov (United States)

    Kim, Sang Bok; Yang, Chuanxi; Powers, Tamara; Davis, Luke M; Lou, Xiabing; Gordon, Roy G

    2016-08-22

    We have prepared two new Ca(II) amidinates, which comprise a new class of ALD precursors. The syntheses proceed by a direct reaction between Ca metal and the amidine ligands in the presence of ammonia. Bis(N,N'-diisopropylformamidinato)calcium(II) (1) and bis(N,N'-diisopropylacetamidinato)calcium(II) (2) adopt dimeric structures in solution and in the solid state. X-ray crystallography revealed asymmetry in one of the bridging ligands to afford the structure [(η(2) -L)Ca(μ-η(2) :η(2) -L)(μ-η(2) :η(1) -L)Ca(η(2) -L)]. These amidinate complexes showed unprecedentedly high volatility as compared to the widely employed and commercially available Ca(II) precursor, [Ca3 (tmhd)6 ]. In CaS ALD with 1 and H2 S, the ALD window was approximately two times wider and lower in temperature by about 150 °C than previously reported with [Ca3 (tmhd)6 ] and H2 S. Complexes 1 and 2, with their excellent volatility and thermal stability (up to at least 350 °C), are the first homoleptic Ca(II) amidinates suitable for use as ALD precursors.

  3. Amidine Sulfonamides and Benzene Sulfonamides: Synthesis and Their Biological Evaluation

    OpenAIRE

    Muhammad Abdul Qadir; Mahmood Ahmed; Hina Aslam; Sadia Waseem; Muhammad Imtiaz Shafiq

    2015-01-01

    New amidine and benzene sulfonamide derivatives were developed and structures of the new products were confirmed by elemental and spectral analysis (FT-IR, ESI-MS, 1HNMR, and 13CNMR). In vitro, developed compounds were screened for their antibacterial and antifungal activities against medically important bacterial strains, namely, S. aureus, B. subtilis, and E. coli, and fungi, namely, A. flavus, A. parasiticus, and A. sp. The antibacterial and antifungal activities have been determined by me...

  4. Synthetic and structural chemistry of amidinate-substituted boron halides.

    Science.gov (United States)

    Hill, Nicholas J; Findlater, Michael; Cowley, Alan H

    2005-10-01

    The following new amidinate-substituted boron halides are reported: [PhC{N(SiMe(3))}(2)]BCl(2)(6), [MeC{NCy}(2)]BCl(2)(10), [Mes*C{NCy}(2)]BCl(2)(11), [MeC{N(i)Pr}(2)]BCl(2)(12), and [FcC{NCy}(2)]BBr(2)(13). Compound 6 was prepared via the trimethylsilyl chloride elimination reaction of BCl(3) with N,N,N'-tris(trimethylsilyl)benzamidine, and compounds 10-12 were prepared by salt metathesis between the lithium amidinates [RC(NR')(2)]Li and BX(3). Compound 13 was prepared via the insertion of 1,3-dicyclohexylcarbodiimide into the B-C bond of ferrocenyldibromoborane FcBBr(2). The molecular structures of 6, 10, 11, 13 and the known compound [PhC{N(SiMe(3))}(2)]BBr(2)(1) were established by single-crystal X-ray diffraction. PMID:16172649

  5. Amidinate Ligands in Zinc coordination sphere: Synthesis and structural diversity

    Indian Academy of Sciences (India)

    SRINIVAS ANGA; INDRANI BANERJEE; TARUN K PANDA

    2016-06-01

    A one-pot reaction involving neosilyllithium and three different carbodiimides (RN=C=NR, R =cyclohexyl, isopropyl and tert-butyl) in diethyl ether, followed by the addition of anhydrous $ZnCl_{2}$, afforded,in high yield, corresponding homoleptic zinc amidinate complexes having the molecular formulae$[Zn{CyN=C(CH_{2}SiMe_{3})NCy}_{2}]$ (1),$[Zn^{{i}PrN=C(CH_{2}SiMe_{3})N^{i}Pr}_{2}]$ (2) and [Zn$^{{t}BuN=C(CH_{2}SiMe_{3})N^{t}Bu}_{2}]$ (3), respectively, and amidinato moieties in the zinc coordination sphere. Solid state structures of complexes1-3 are reported thereafter - all the three complexes are isostructural, and each of them consists of twofour-membered metallacycles.

  6. Amidine-bearing lipoplex targeting to hepatocyte cells

    Institute of Scientific and Technical Information of China (English)

    Yasuya Kudo; Kazunori Koiwai; Kazuhiro Shimizu; Shota Kusuki; Mina Sakuragi; Naohiko Shimada; Yoichi Takeda; Kazuo Sakurai

    2008-01-01

    A lipoplex (i.e., pDNA#1/lipid complex and transfection reagent for pDNA delivery) containing galactosylceramide (GalCer) and an amidine-bearing lipid (TRX) was examined whether the bound pDNA was specifically ingested by hepatocyte via asialoglycoprotein receptor (ASGPR) and then expressed protein. Gel electrophoresis and small-angle X-ray scattering (SAXS) confirmed that the TRX-GalCer liposome#2 complexed with pDNA and the resultant lipoplex took a hexagonally packed inverted cylinder structure when the GalCer composition was less than 20 wt.% of the total lipid. When the lipoplex carrying pGL3 (luciferase-cording pDNA) was administrated to HepG2, the luciferase activity was increased with increasing the GalCer composition until it reached 3 wt.% and then decreased upon further addition of GalCer. When we added galactose itself as a competitor, the luciferase activity was decreased, while glucose did not show such decrease, suggesting that HepG2 ingested the lipoplex via ASGPR-mediated endocytosis. This paper indicated that the hexagonally packed inverted cylinder structures of lipoplex may not always provide excellent transfection and presented a possibility that the TRX lipoplex#3 can obtain a cellular-targeting ability through the receptors for oligosaccharide.

  7. Amidine Sulfonamides and Benzene Sulfonamides: Synthesis and Their Biological Evaluation

    Directory of Open Access Journals (Sweden)

    Muhammad Abdul Qadir

    2015-01-01

    Full Text Available New amidine and benzene sulfonamide derivatives were developed and structures of the new products were confirmed by elemental and spectral analysis (FT-IR, ESI-MS, 1HNMR, and 13CNMR. In vitro, developed compounds were screened for their antibacterial and antifungal activities against medically important bacterial strains, namely, S. aureus, B. subtilis, and E. coli, and fungi, namely, A. flavus, A. parasiticus, and A. sp. The antibacterial and antifungal activities have been determined by measuring MIC values (μg/mL and zone of inhibitions (mm. Among the tested compounds, it was found that compounds 3b, 9a, and 9b have most potent activity against S. aureus, A. flavus, and A. parasiticus, respectively, and were found to be more active than sulfamethoxazole and itraconazole with MIC values 40 μg/mL. In contrast, all the compounds were totally inactive against the A. sp. except 10b and 15b to show activity to some extent.

  8. CO(2) adsorption on supported molecular amidine systems on activated carbon.

    Science.gov (United States)

    Alesi, W Richard; Gray, McMahan; Kitchin, John R

    2010-08-23

    The CO(2) capture capacities for typical flue gas capture and regeneration conditions of two tertiary amidine N-methyltetrahydropyrimidine (MTHP) derivatives supported on activated carbon were determined through temperature-controlled packed-bed reactor experiments. Adsorption-desorption experiments were conducted at initial adsorption temperatures ranging from 29 degrees C to 50 degrees C with temperature-programmed regeneration under an inert purge stream. In addition to the capture capacity of each amine, the efficiencies at which the amidines interact with CO(2) were determined. Capture capacities were obtained for 1,5-diazo-bicyclo[4.3.0]non-5-ene (DBN) and 1,8-diazobicyclo[5.4.0]-undec-7-ene (DBU) supported on activated carbon at a loading of approximately 2.7 mol amidine per kg of sorbent. Moisture was found to be essential for CO(2) capture on the amidines, but parasitic moisture sorption on the activated carbon ultimately limited the capture capacities. DBN was shown to have a higher capture capacity of 0.8 mol CO(2) per kg of sorbent and an efficiency of 0.30 mol CO(2) per mol of amidine at an adsorption temperature of 29 degrees C compared to DBU. The results of these experiments were then used in conjunction with a single-site adsorption model to derive the Gibbs free energy for the capture reaction, which can provide information about the suitability of the sorbent under different operating conditions. PMID:20730982

  9. Exploiting the Divalent Nature of Isonitriles: a novel Pictet-Spengler Amidination process.

    Science.gov (United States)

    Medda, Federico; Hulme, Christopher

    2014-05-01

    An isocyanide-based multicomponent reaction (IMCR) utilized for the rapid assembly of novel, biologically relevant dihydropyrrolo[1,2-a]quinoxalines-amidines is herein presented. Starting from 1-(2-aminophenyl)pyrroles, aldehydes, and isonitriles, the target heterocyclic scaffold is assembled in a one-pot, operationally friendly process. With three points of diversity and formation of three chemical bonds in one step, this strategy proves to be very general. Novel, mild methodology for the generation of amidines from secondary amine anilines and isonitriles is also introduced. PMID:24954960

  10. Synthesis and Characterization of Ruthenium Amidinate Complexes as Precursors for Vapor Deposition

    OpenAIRE

    Gordon, Roy Gerald; Lim, Booyong S.; Li, Zhengwen; Aaltonen, Titta; Li, Huazhi

    2008-01-01

    Three new ruthenium amidinate complexes were prepared: tris(diisopropylacetamidinato)-ruthenium(III), Ru(iPrNC(Me)NiPr)3 4; bis(diisopropyl-acetamidinato)ruthenium(II) dicarbonyl, Ru(iPrNC(Me)NiPr)2(CO)2 5; and bis(ditert- butylacetamidinato)ruthenium(II) dicarbonyl, Ru(tBuNC(Me)NtBu)2(CO)2 6. They have been synthesized and characterized by 1H NMR, TG and X-ray structure analysis. These three complexes were found to be monomeric and air stable. Compound 6 was found to have sufficient volatili...

  11. Protein kinase A of Leishmania amazonensis as a potential target for methoxy-amidine.

    Science.gov (United States)

    Genestra, M; Echevarria, A; Cysne-Finkelstein, L; Leon, L L

    2001-11-01

    Cyclic 3',5'-adenosine monophosphate (cAMP) is one of the most important signaling molecules for cell growth and differentiation in several systems including protozoal parasites such as Trypanosoma cruzi and Leishmania species. The most important event during Leishmania developmental cycle is the differentiation of procyclic into metacyclic promastigotes, which is associated with the appearance of pathogenicity. As previously demonstrated Leishmania amazonensis metacyclogenesis is associated with an increase of a protein kinase A activity, and therefore further studies on the activity of this phosphorylating enzyme as a target for chemotherapy were performed. Among several amidine derivatives tested by the authors against trypanosomatids (T. cruzi, T. evansi and L. amazonensis) the most effective compounds was defined as that with a methoxy group as substituent. In this work the inhibitory effect of this derivative on the phosphorylating activity of cAMP-dependent protein kinase (PKA) of promastigotes (containing high amounts of metacyclic forms) and axenic amastigotes of L. amazonensis is demonstrated. Soluble fractions (SF) and enriched membrane fractions (MF) were submitted to anion exchange chromatography in a DEAE-cellulose column and the collected fractions used to evaluate the phosphorylating activity associated with cAMP, in the presence/absence of methoxy-amidine and pentamidine (CAS 100-33-4), the latter being used as reference drug. PMID:11765595

  12. Novel amidines and analogues as promising agents against intracellular parasites: a systematic review.

    Science.gov (United States)

    Soeiro, M N C; Werbovetz, K; Boykin, D W; Wilson, W D; Wang, M Z; Hemphill, A

    2013-07-01

    Parasitic protozoa comprise diverse aetiological agents responsible for important diseases in humans and animals including sleeping sickness, Chagas disease, leishmaniasis, malaria, toxoplasmosis and others. They are major causes of mortality and morbidity in tropical and subtropical countries, and are also responsible for important economic losses. However, up to now, for most of these parasitic diseases, effective vaccines are lacking and the approved chemotherapeutic compounds present high toxicity, increasing resistance, limited efficacy and require long periods of treatment. Many of these parasitic illnesses predominantly affect low-income populations of developing countries for which new pharmaceutical alternatives are urgently needed. Thus, very low research funding is available. Amidine-containing compounds such as pentamidine are DNA minor groove binders with a broad spectrum of activities against human and veterinary pathogens. Due to their promising microbicidal activity but their rather poor bioavailability and high toxicity, many analogues and derivatives, including pro-drugs, have been synthesized and screened in vitro and in vivo in order to improve their selectivity and pharmacological properties. This review summarizes the knowledge on amidines and analogues with respect to their synthesis, pharmacological profile, mechanistic and biological effects upon a range of intracellular protozoan parasites. The bulk of these data may contribute to the future design and structure optimization of new aromatic dicationic compounds as novel antiparasitic drug candidates.

  13. Amidines for Versatile Cobalt(III)-Catalyzed Synthesis of Isoquinolines through C-H Functionalization with Diazo Compounds.

    Science.gov (United States)

    Li, Jie; Tang, Mengyao; Zang, Lei; Zhang, Xiaolei; Zhang, Zhao; Ackermann, Lutz

    2016-06-01

    A cobalt(III)-catalyzed C-H/N-H bond functionalization for the synthesis of 1-aminoisoquinolines from aryl amidines and diazo compounds has been developed. The reaction proceeds under mild reaction conditions, obviates the need for oxidants, produces only N2 and H2O as the byproducts, and features a broad substrate scope. PMID:27219713

  14. Highly fluorescent amidine/schiff base dual-modified polyacrylonitrile nanoparticles for selective and sensitive detection of copper ions in living cells.

    Science.gov (United States)

    Lee, Inkyu; Kim, Sojin; Kim, Seh-Na; Jang, Yoonsun; Jang, Jyongsik

    2014-10-01

    Highly fluorescent surface modified polyacrylonitrile nanoparticles (PAN NPs) of 50 nm diameter were fabricated for selective Cu(2+) sensing. After surface modification, the PAN NPs were converted to amidine/Schiff base dual-modified PAN nanoparticles (tPAN NPs) with a Cu(2+) sensing property and high QY (0.19). The selectivity of tPAN NPs for Cu(2+) is much higher than that of other metal ions due to the fact that amidine group on the surface of tPAN NPs has a higher binding affinity with Cu(2+). The effect of other metal ions on the fluorescence intensity of the tPAN NPs was also studied, and other metal ions showed a low interference response in the detection of Cu(2+). Furthermore, as a metal ion chelator, ethylenediaminetetraacetate can competitively interact with Cu(2+) to recover the quenched fluorescence of tPAN NPs. The tPAN NPs are easily introduced into cells and exhibit low toxicity, enabling their use as a fluorescence sensor for Cu(2+) in living cells. The tPAN NPs provide a new direction for the development of copper ion sensors in living cells. PMID:25197957

  15. Bis(alkyl) rare-earth complexes supported by a new tridentate amidinate ligand with a pendant diphenylphosphine oxide group. Synthesis, structures and catalytic activity in isoprene polymerization.

    Science.gov (United States)

    Tolpygin, Aleksei O; Glukhova, Tatyana A; Cherkasov, Anton V; Fukin, Georgy K; Aleksanyan, Diana V; Cui, Dongmei; Trifonov, Alexander A

    2015-10-01

    A new tridentate amidine 2-[Ph2P(O)]C6H4NHC(tBu)[double bond, length as m-dash]N(2,6-Me2C6H3) (1) bearing a side chain pendant Ph2P[double bond, length as m-dash]O group was synthesized and proved to be a suitable ligand for coordination to rare-earths ions. Bis(alkyl) complexes {2-[Ph2P(O)]C6H4NC(tBu)N(2,6-Me2C6H3)}Ln(CH2SiMe3)2(THF)n (Ln = Y, n = 1 (3), Ln = Er, n = 1 (4), Ln = Lu, n = 0 (5)) were prepared using alkane elimination reactions of and Ln(CH2SiMe3)3(THF)2 (Ln = Y, Er, Lu) in hexane and were isolated in 50, 70 and 75% yields respectively. The X-ray studies revealed that complexes 2-5 feature intramolecular coordination of P[double bond, length as m-dash]O groups to metal ions. The lutetium complex 5 proved to be rather stable: at 20 °C its half-life time is 1155 h, while for the yttrium analogue the half-life time was found to be 63 h. Complexes 3-5 were evaluated as precatalysts for isoprene polymerization. The systems Ln/borate/AliBu3 (Ln = 3-5, borate = [PhNHMe2][B(C6F5)4], [Ph3C][B(C6F5)4]) turned out to be highly efficient in isoprene polymerization and enable complete conversion of 1000-10,000 equivalents of monomer into polymer at 20 °C within 0.5-2.5 h affording polyisoprenes with a very high content of 1,4-cis units (up to 96.6%) and from narrow (1.49) to moderate (3.54) polydispersities. A comparative study of catalytic performance of the related bis(alkyl) yttrium complexes supported by amidinate ligands of different denticities and structures [tBuC(N-2,6iPr2C6H4)2](-), [tBuC(N-2,6-iPr2C6H4)(N-2-MeOC6H4)](-) and {2-[Ph2P(O)]C6H4NC(tBu)N(2,6-Me2C6H3)}(-) demonstrated that the introduction of a pendant donor group (2-MeOC6H4 or Ph2P(O)) into a side chain of amidinate scaffolds results in a significant increase in catalytic activity. The amidinate ligand bearing a Ph2P(O)-group provides a high isoprene polymerization rate along with excellent control over regio- and stereoselectivities and allows us to obtain polyisoprenes with a reasonable

  16. Integrated control of acaricide-resistant Boophilus microplus populations on grazing cattle in Mexico using vaccination with Gavac and amidine treatments.

    Science.gov (United States)

    Redondo, M; Fragoso, H; Ortíz, M; Montero, C; Lona, J; Medellín, J A; Fría, R; Hernández, V; Franco, R; Machado, H; Rodríguez, M; de la Fuente, J

    1999-10-01

    Throughout most of the twentieth century, tick infestations on cattle have been controlled with chemical acaricides, typically administered by dipping or spraying. This approach can cause environmental and residue problems and has created a high incidence of acaricide resistance within tick populations in the field. Recently we developed a vaccine against Boophilus microplus employing a recombinant Bm86 antigen preparation (Gavac), (Heber Biotec S.A., Havana, Cuba) which has been shown to induce a protective response in vaccinated animals. Here we show for the first time under field conditions a near 100% control of B. microplus populations resistant to pyrethroids and organophosphates, by an integrated system employing vaccination with Gavac and amidine treatments. This method effectively controls tick infestations while reducing the number of chemical acaricide treatments and consequently the rise of B. microplus populations resistant to chemical acaricides. PMID:10581714

  17. Abiotic amidine and guanidine hydrolysis of lamotrigine-N2-glucuronide and related compounds in wastewater: The role of pH and N2-substitution on reaction kinetics.

    Science.gov (United States)

    Zonja, Bozo; Delgado, Antonio; Abad, J Luis; Pérez, Sandra; Barceló, Damià

    2016-09-01

    The stability of lamotrigine (LMG) and its principal human metabolite, lamotrigine N2-glucuronide (LMG-N2-G), was studied as a function of pH (4-9). While LMG was stable across the entire pH range, under neutral-basic conditions, LMG-N2-G was converted to three transformation products (TPs) which were identified using high resolution mass spectrometry (HRMS). The MS fragmentation studies indicated that two TPs were the result of the hydrolysis of the amidine and guanidine moieties. The third TP detected was an intermediate in the guanidine hydrolysis reaction. In order to evaluate the transformation kinetics of the LMG-N2-G degradation, another set of pH-dependent experiments was carried out in hospital effluent, wastewater influent and effluent spiked at 20 and 200 nM after pH adjustment (pH 6.5, 7, 8, 8.5 and 9), demonstrating that, at higher pH, LMG-N2-G is degraded at higher rate. Later, the pH-dependent stability of related compounds with different nitrogen N2-substituents (N2-R) on the 1,2,4-triazine ring was studied. This revealed that because of different imino tautomer equilibrium LMG (N2-H) and LMG-N2-oxide ((+)N2-O(-)) were stable at all pHs but N2-methyl-LMG (N2-CH3) as well as LMG-N2-G were susceptible to amidine and guanidine hydrolysis at basic pH. Finally, hospital effluent samples collected over the course of one week were monitored for their presence. LMG, LMG-N2-G and two of its TPs were detected with concentrations ranging between 0.01 and 1 μgL(-1). PMID:27232991

  18. Molecular design, synthesis and biological activities of amidines as new ketol-acid reductoisomerase inhibitors

    Institute of Scientific and Technical Information of China (English)

    Bao Lei Wang; Yong Hong Li; Jian Guo Wang; Yi Ma; Zheng Ming Li

    2008-01-01

    Diamidine (A) was identified in our in vitro bio-assay as a possible inhibitor of ketol-acid reductoisomerase (KARI) from the ACD database search based on the known three-dimensional crystal structure of KARI. An investigation on interaction of A on KARI active sites, led to the design and synthesis of 15 novel monoamidines. Some of those showed better biological activity than A on rice KARI (in vitro) and in greenhouse herbicidal tests (in vivo). The structure-biological activity relationship was investigated, which provides valuable information to further study of potential KARI inhibitors.

  19. New amidines from intramolecular cyclization in triflic acid of nitroketene aminals with a tethered phenyl ring

    Indian Academy of Sciences (India)

    Soro Yaya; Bamba Fanté; Siaka Sorho; Coustard Jean-Marie; Adima A Augustin

    2007-05-01

    Nitroketene aminals with a tethered phenyl group underwent an intramolecular cyclization in trifluoromethanesulfonic acid to afford the corresponding N-(3-ethyl-hydrohydroxyiminobenzocycloalkenylidene) methylamine trifluoromethanesulfonate. The yields were fair to good excepted for the starting compound 1-[N-ethyl-N-(2-phenylethyl)amino]-1-methylamino-2-nitroethene.

  20. Effection of UV-LED Illuminant on the Curation of Photolatent-amidine Mixed with Bisphenol A Epoxy Acrylate under Printing Conditions

    Directory of Open Access Journals (Sweden)

    Duan Huawei

    2016-01-01

    Full Text Available In order to make photocuring ink or coating cured by UV-LED illuminant, we synthesized (4-((hexahydropyrrolo[1,2-a]pyrimidin-1 (2H-ylmethylphenyl(phenylmethanone(PL -DBN and (4-((octahydropyrimido[1,2-a]azepin-1(2H-ylmethylphenyl(phenylmet hanone(PL -DBU as photoinitiators. Different mass fraction of the photoinitiators was mixed with bisphenol A epoxy acrylate, cured by different wavelengths and power of UV-LED illuminant,and investigated the curing effects of photoinitiators on bisphenol A epoxy acrylate. The results show that the conversion of C=C double bonds of bisphenol A epoxy acrylate will increase as the mass fraction of the photoinitiators or the power of UV-LED illuminant increase. In the same conditions, the curing effect of using 365nm UV-LED illuminant on bisphenol A epoxy acrylate is better than using 395nm UV-LED illuminant. PL-DBU has a better curing effect on the bisphenol A epoxy acrylate rather than PL-DBN. When using the 8W/cm2 of 365nm UV-LED illuminant to cure a mixture of 3% PL-DBU and 97% bisphenol A epoxy acrylate, it will be dry completely in 2 seconds, moreover, the conversion reach 79%.

  1. Experimental Chemotherapy for Chagas Disease: A Morphological, Biochemical, and Proteomic Overview of Potential Trypanosoma cruzi Targets of Amidines Derivatives and Naphthoquinones.

    Science.gov (United States)

    de Castro, Solange L; Batista, Denise G J; Batista, Marcos M; Batista, Wanderson; Daliry, Anissa; de Souza, Elen M; Menna-Barreto, Rubem F S; Oliveira, Gabriel M; Salomão, Kelly; Silva, Cristiane F; Silva, Patricia B; Soeiro, Maria de Nazaré C

    2011-01-01

    Chagas disease (CD), caused by Trypanosoma cruzi, affects approximately eight million individuals in Latin America and is emerging in nonendemic areas due to the globalisation of immigration and nonvectorial transmission routes. Although CD represents an important public health problem, resulting in high morbidity and considerable mortality rates, few investments have been allocated towards developing novel anti-T. cruzi agents. The available therapy for CD is based on two nitro derivatives (benznidazole (Bz) and nifurtimox (Nf)) developed more than four decades ago. Both are far from ideal due to substantial secondary side effects, limited efficacy against different parasite isolates, long-term therapy, and their well-known poor activity in the late chronic phase. These drawbacks justify the urgent need to identify better drugs to treat chagasic patients. Although several classes of natural and synthetic compounds have been reported to act in vitro and in vivo on T. cruzi, since the introduction of Bz and Nf, only a few drugs, such as allopurinol and a few sterol inhibitors, have moved to clinical trials. This reflects, at least in part, the absence of well-established universal protocols to screen and compare drug activity. In addition, a large number of in vitro studies have been conducted using only epimastigotes and trypomastigotes instead of evaluating compounds' activities against intracellular amastigotes, which are the reproductive forms in the vertebrate host and are thus an important determinant in the selection and identification of effective compounds for further in vivo analysis. In addition, due to pharmacokinetics and absorption, distribution, metabolism, and excretion characteristics, several compounds that were promising in vitro have not been as effective as Nf or Bz in animal models of T. cruzi infection. In the last two decades, our team has collaborated with different medicinal chemistry groups to develop preclinical studies for CD and investigate the in vitro and in vivo efficacy, toxicity, selectivity, and parasite targets of different classes of natural and synthetic compounds. Some of these results will be briefly presented, focusing primarily on diamidines and related compounds and naphthoquinone derivatives that showed the most promising efficacy against T. cruzi. PMID:22091400

  2. Experimental Chemotherapy for Chagas Disease: A Morphological, Biochemical, and Proteomic Overview of Potential Trypanosoma cruzi Targets of Amidines Derivatives and Naphthoquinones

    Directory of Open Access Journals (Sweden)

    Solange L. de Castro

    2011-01-01

    Full Text Available Chagas disease (CD, caused by Trypanosoma cruzi, affects approximately eight million individuals in Latin America and is emerging in nonendemic areas due to the globalisation of immigration and nonvectorial transmission routes. Although CD represents an important public health problem, resulting in high morbidity and considerable mortality rates, few investments have been allocated towards developing novel anti-T. cruzi agents. The available therapy for CD is based on two nitro derivatives (benznidazole (Bz and nifurtimox (Nf developed more than four decades ago. Both are far from ideal due to substantial secondary side effects, limited efficacy against different parasite isolates, long-term therapy, and their well-known poor activity in the late chronic phase. These drawbacks justify the urgent need to identify better drugs to treat chagasic patients. Although several classes of natural and synthetic compounds have been reported to act in vitro and in vivo on T. cruzi, since the introduction of Bz and Nf, only a few drugs, such as allopurinol and a few sterol inhibitors, have moved to clinical trials. This reflects, at least in part, the absence of well-established universal protocols to screen and compare drug activity. In addition, a large number of in vitro studies have been conducted using only epimastigotes and trypomastigotes instead of evaluating compounds' activities against intracellular amastigotes, which are the reproductive forms in the vertebrate host and are thus an important determinant in the selection and identification of effective compounds for further in vivo analysis. In addition, due to pharmacokinetics and absorption, distribution, metabolism, and excretion characteristics, several compounds that were promising in vitro have not been as effective as Nf or Bz in animal models of T. cruzi infection. In the last two decades, our team has collaborated with different medicinal chemistry groups to develop preclinical studies for CD and investigate the in vitro and in vivo efficacy, toxicity, selectivity, and parasite targets of different classes of natural and synthetic compounds. Some of these results will be briefly presented, focusing primarily on diamidines and related compounds and naphthoquinone derivatives that showed the most promising efficacy against T. cruzi.

  3. Divergent reactivity of nitric oxide with metal-metal quintuple bonds.

    Science.gov (United States)

    Wu, Pei-Fang; Liu, Shih-Cheng; Shieh, Yun-Jen; Kuo, Ting-Shen; Lee, Gene-Hsiang; Wang, Yu; Tsai, Yi-Chou

    2013-05-14

    Reactions of NO with the quintuple bonded chromium and molybdenum amidinate dimers, respectively, gave dichromium nitrosyl nitrito amidinato complexes, and the quadruple bonded dimolybdenum nitrito amidinato species with a paddlewheel configuration.

  4. Chiral benzamidinate ligands in rare-earth-metal coordination chemistry.

    Science.gov (United States)

    Benndorf, Paul; Kratsch, Jochen; Hartenstein, Larissa; Preuss, Corinna M; Roesky, Peter W

    2012-11-01

    The treatment of the recently reported potassium salt (S)-N,N'-bis-(1-phenylethyl)benzamidinate ((S)-KPEBA) and its racemic isomer (rac-KPEBA) with anhydrous lanthanide trichlorides (Ln = Sm, Er, Yb, Lu) afforded mostly chiral complexes. The tris(amidinate) complex [{(S)-PEBA}(3)Sm], bis(amidinate) complexes [{Ln(PEBA)(2)(μ-Cl)}(2)] (Ln = Sm, Er, Yb, Lu), and mono(amidinate) compounds [Ln(PEBA)(Cl)(2)(thf)(n)] (Ln = Sm, Yb, Lu) were isolated and structurally characterized. As a result of steric effects, the homoleptic 3:1 complexes of the smaller lanthanide atoms Yb and Lu were not accessible. Furthermore, chiral bis(amidinate)-amido complexes [{(S)-PEBA}(2)Ln{N(SiMe(3))(2)}] (Ln = Y, Lu) were synthesized by an amine-elimination reaction and salt metathesis. All of these chiral bis- and tris(amidinate) complexes had additional axial chirality and they all crystallized as diastereomerically pure compounds. By using rac-PEBA as a ligand, an achiral meso arrangement of the ligands was observed. The catalytic activities and enantioselectivities of [{(S)-PEBA}(2)Ln{N(SiMe(3))(2)}] (Ln = Y, Lu) were investigated in hydroamination/cyclization reactions. A clear dependence of the rate of reaction and enantioselectivity on the ionic radius was observed, which showed higher reaction rates but poorer enantioselectivities for the yttrium compound. PMID:23015310

  5. Design, synthesis, and biological evaluation of pyrazinones containing novel P1 needles as inhibitors of TF/VIIa.

    Science.gov (United States)

    Trujillo, John I; Huang, Horng-Chih; Neumann, William L; Mahoney, Matthew W; Long, Scott; Huang, Wei; Garland, Danny J; Kusturin, Carrie; Abbas, Zaheer; South, Michael S; Reitz, David B

    2007-08-15

    Herein is described the design, synthesis, and enzymatic activity of a series of substituted pyrazinones as inhibitors of the TF/VIIa complex. These inhibitors were designed to explore replacement and variation of the P1 amidine described previously [J. Med. Chem.2003, 46, 4050]. The P1 needle replacements were selected based upon their reduced basicity compared to the parent phenyl amidine (pKa approximately 12). A contributing factor towards the oral bioavailability of a compound is the ionization state of the compound in the intestinal tract. The desired outcome of the study was to identify an orally bioavailable TF-VIIa inhibitor. PMID:17566736

  6. Chemistry of isoflavone heterocyclic analogs. 10. Synthesis of pyrimidines by recyclization of isoflavones and their heterocyclic analogs

    Energy Technology Data Exchange (ETDEWEB)

    Khilya, V.P.; Kornilov, M.Yu.; Gorbulenko, N.V.; Golubushina, G.M.; Kovtun, E.N.; Kolotusha, N.V.; Panasenko, G.V.

    1986-05-01

    Isoflavones and their thiazole and pyrazole analogs are recyclized into the corresponding 4-(2-hydroxyphenyl)-pyrimidine derivatives under the effect of amidines. Their PMR spectra were studied. The effects related to the formation and strength of the intramolecular hydrogen bond were examined.

  7. Perfluroaryl azides : Reactivities, Unique Reactions and their Applications in the Synthesis of Theranostic Agents

    OpenAIRE

    Xie, Sheng

    2015-01-01

    The work centersaround perfluoroaryl azides (PFAAs), and theirability to undergo certain fast and robusttransformations. The chemistry was furtherappliedfor biomedical applications. The first section focuses on the azide-aldehyde-amine cycloaddition using PFAAs. Experimental and computational investigations uncovered a fast azide-enamine cycloaddition to form triazolines, which spontaneously rearrange into stable amidine products. In addition, this transformation was explored in the formulati...

  8. Selective Synthesis of Isoquinolines by Rhodium(III)-Catalyzed C-H/N-H Functionalization with α-Substituted Ketones.

    Science.gov (United States)

    Li, Jie; Zhang, Zhao; Tang, Mengyao; Zhang, Xiaolei; Jin, Jian

    2016-08-01

    A rhodium(III)-catalyzed C-H/N-H bond functionalization for the synthesis of 1-aminoisoquinolines from aryl amidines and α-MsO/TsO/Cl ketones was achieved under mild reaction conditions. Thus, this approach provides a practical method for the site-selective synthesis of various synthetically valuable isoquinolines with wide functional group tolerance. PMID:27441726

  9. Carbon-14 labelled nitrogen heterocycles; the syntheses of three phosphodiesterase inhibitors

    International Nuclear Information System (INIS)

    The syntheses of three heterocyclic phosphodiesterase inhibitors are described from a common radiolabelled precursor, namely 2-propoxybenzo[cyano-14C] nitrile. Conversion of the nitrile to the corresponding methyl ketone or amidine allows elaboration of the heterocycles radiolabelled within the ring systems. (Author)

  10. Inhibition of RNA synthesis in vitro and cell growth by anthracycline antibiotics.

    Science.gov (United States)

    Studzian, K; Wasowska, M; Piestrzeniewicz, M K; Wilmańska, D; Szmigiero, L; Oszczapowicz, I; Gniazdowski, M

    2001-01-01

    New derivatives of doxorubicin and daunorubicin with amidine group bonded to daunosamine at C-3' atom and bearing the morpholine ring attached to the amidine group have been recently synthesized. Their cytotoxic activities and effects on RNA synthesis in vitro were assayed. The drug concentrations inhibiting mouse leukaemia L1210 cell growth to 50% were about two- and three fold higher for the derivatives compared to doxorubicin and daunorubicin respectively. Inhibition of phage T7 RNA polymerase by the non-covalently interacting derivatives was also slightly lower than that by the parent compounds. As doxorubicin and daunorubicin, their amidine derivatives in the presence of dithiothreitol and Fe(III) ions are activated and covalently bind to DNA. The adducts formed affect RNA polymerase activity. Several bands corresponding to prematurely terminated RNA chains are observed by means of polyacrylamide gel electrophoresis. The patterns of bands are virtually identical for all the anthracyclines studied here and are similar to the terminations induced by actinomycin D. This observation is consistent with a notion that the adducts are formed at guanine in GpC sequences which are also binding sites of actinomycin D. A substantial difference between daunorubicin and its amidine derivative is shown by means of high performance liquid chromatography. The derivative undergoes rapid rearrangements in the presence of dithiothreitol and Fe(III) ions, while daunorubicin is stable for several hours under these conditions. The results presented here indicate that the amidine derivatives despite bulky morpholine substitution exhibit biological activity in the systems used here. PMID:11845988

  11. Reaction of Tosylmethyl Isocyanide with N-Heteroaryl Formamidines: an Alternative Approach to the Synthesis of N-Heteroaryl Tosylimidazoles

    Energy Technology Data Exchange (ETDEWEB)

    Gomezgarcia, Omar; Salgadozamora, Hector; Reyesarellano, Aliciam; Camposaldrete, Elena; Peraltacruz, Javier [Departamento Quimica Organica, Colonia (Mexico)

    2013-09-15

    In conclusion, an alternative procedure was developed under mild conditions for the synthesis of 2-(4-tosylimidazo-1-yl)pyridines and pyrimidines by the reaction of TosMIC with the corresponding heteroaryl N,N'-dimethyl form-amidines. This approach does not involve a nucleophilic displacement of a leaving group and constitutes a further application of amidines, in which TosMIC acts as both a nucleophile and an electrophile on the heteroaryl formamidine. This process offers advantages over previously reported procedures. Tosyl methyl isocyanide (TosMIC), a multipurpose commercially available 3-unit synthon introduced by Van Leusen, reacts with a variety of groups to give heterocycles. It is important to emphasize that treatment of TosMIC with various functional groups leads to the formation of the imidazole nucleus, such as is the case with imines, imidoyl chlorides, isothiocyanates, nitrile and ethoxy methylene amino. However, only the latter group yields N-heterocycle imidazoles.

  12. Evaluation of the Efficacy of Acaricides Used to Control the Cattle Tick, Rhipicephalus microplus, in Dairy Herds Raised in the Brazilian Southwestern Amazon.

    Science.gov (United States)

    Brito, Luciana G; Barbieri, Fábio S; Rocha, Rodrigo B; Oliveira, Márcia C S; Ribeiro, Elisana Sales

    2011-01-01

    The adult immersion test (AIT) was used to evaluate the efficacy of acaricide molecules used for control of Rhipicephalus microplus on 106 populations collected in five municipalities in the state of Rondônia in the Brazilian South Occidental Amazon region. The analysis of the data showed that the acaricide formulations had different efficacies on the tick populations surveyed. The synthetic pyrethroids (SPs) acaricides were the least effective (48.35-76.84%), followed by SP + organophosphate (OP) associations (68.91-81.47%) and amidine (51.35-100%). For the macrocyclic lactones (MLs), the milbemycin (94.84-100%) was the most effective, followed by spinosad (93.21-100%) and the avermectins (81.34-100%). The phenylpyrazole (PZ) group had similar efficacy (99.90%) to the MLs. Therefore, SP acaricides, including associations with OP, and formulations based on amidine presented low in vitro efficacy to control the R. microplus populations surveyed. PMID:21547224

  13. Sequence specificity of formaldehyde-mediated covalent binding of anthracycline derivatives to DNA.

    Science.gov (United States)

    Szulawska, Agata; Gniazdowski, Marek; Czyz, Malgorzata

    2005-01-01

    Daunorubicin (DRB) and doxorubicin (DOX) in the presence of formaldehyde (CH2O) form covalent adducts with DNA. A G-specific adduct is formed by producing an aminal bridge between the C-3' of daunosamine and the C-2 of guanine. New derivatives of DRB, DOX and epidoxorubicin (EDOX) with an amidine group bonded to the C-3' of the daunosamine moiety, with either a morpholine or hexamethyleneimine ring attached to the amidine group, were studied in this paper. DNase I footprinting and analyses with restriction endonucleases were applied to compare the specificity of adduct formed by the amidine derivatives and their parent compounds. These approaches provide consistent results, proving that a GC pair is required for covalent binding of anthracycline derivatives to DNA and that different flanking sequences are able to modify the sequence preference of the drugs. The 5'-GC-3', 5'-CG-3' and 5'-TC-3' sequences were protected most efficiently by the parent compounds and their morpholine derivatives and some increased protection of 5'-TC-3' sequence was observed for morpholine analogues. Hexamethyleneimine derivatives bind to DNA with much lower efficiency. Finally, the sequence specificity of anthracycline derivatives was correlated with their ability to inhibit binding of transcription factors Sp1 and AP-1 to their DNA recognition sequences. The anthracycline derivatives were more potent in inhibiting Sp1 binding to its cognate GC box than in preventing AP-1 from binding to its mixed A.T and G.C site. Overall, the results indicate that the amidine derivatives of anthracyclines show similar, but not identical sequence specificity as parent compounds, though they exert their effect at a higher concentration. PMID:15588709

  14. Expanding the coordination chemistry of donor-stabilized group-14 metalenes

    OpenAIRE

    Cabeza de Marco, Javier Ángel; García Álvarez, Pablo; Polo Coca, Diego

    2013-01-01

    The transformation of an amidinate germylene, equipped with just one accessible lone pair of electrons on the Ge atom, into a bidentate 4-electron donor κ(2)Ge,N-ligand, has been achieved for the first time, opening new doors to the non-carbene-like coordination chemistry of heavier carbene analogues. [Available from: http://www.researchgate.net/publication/233537999_Expanding_the_coordination_chemistry_of_donor-stabilized_group-14_metalenes [accessed Jul 13, 2015].

  15. Chemistry of polyhalogenated nitrobutadienes, 10: Synthesis of highly functionalized heterocycles with a rigid 6-amino-3-azabicyclo[3.1.0]hexane moiety

    OpenAIRE

    Zapol'skii, Viktor A.; Namyslo, Jan C.; Armin de Meijere; Kaufmann, Dieter E

    2012-01-01

    The nitropolychlorobutadienes 3, 4 are valuable building blocks for various amination and successive heterocyclization products. Nucleophilic substitution reactions of the partially protected, bioactive amines 1, 2 with either vinyl, imidoyl or carbonyl chlorides result in the formation of the enamines 11, 12, 13, 16, 25, the amidine 6, and the amides 20, 21, respectively. In the following, cyclization to the highly functionalized pyrazoles 27, 28, pyrimidine 26 and pyridopyrimidine 24 succee...

  16. Nitric oxide synthase inhibitors containing the carboxamidine group or its isosteres

    Science.gov (United States)

    Proskuryakov, Sergei Ya; Konoplyannikov, Anatoly G.; Skvortzov, Valery G.; Mandrugin, Andrey A.; Fedoseev, Vladimir M.

    2005-09-01

    The review summarises structures, activities and selectivity of NO-synthase (NOS) inhibitors belonging to various classes of chemical compounds. Linear, cyclic and heterocyclic structures containing guanidine, amidine and/or isothiourea fragments are considered. The structure-activity relationships for these inhibitors were analysed in relation to their action on the inducible NOS isoform. This analysis can provide the basis for the synthesis of new more efficient compounds.

  17. Fabrication of CO2 Facilitated Transport Channels in Block Copolymer through Supramolecular Assembly

    Directory of Open Access Journals (Sweden)

    Yao Wang

    2014-05-01

    Full Text Available In this paper, the molecule 12-amidine dodecanoic acid (M with ending groups of carboxyl and amidine groups respectively was designed and synthesized as CO2-responsive guest molecules. The block copolymer polystyrene-b-polyethylene oxide (PS-b-PEO was chosen as the host polymer to fabricate a composite membrane through H-bonding assembly with guest molecule M. We attempted to tune the phase separation structure of the annealed film by varying the amount of M added, and investigated the nanostructures via transmission electron microscope (TEM, fourier transform infrared (FT-IR etc. As a result, a reverse worm-like morphology in TEM image of bright PS phase in dark PEO/M matrix was observed for PS-b-PEO/M1 membrane in which the molar ratio of EO unit to M was 1:1. The following gas permeation measurement indicated that the gas flux of the annealed membranes dramatically increased due to the forming of ordered phase separation structure. As we expected, the obtained composite membrane PS-b-PEO/M1 with EO:M mole ratio of 1:1 presented an evident selectivity for moist CO2 permeance, which is identical with our initial proposal that the guest molecule M in the membranes will play the key role for CO2 facilitated transportation since the amidine groups of M could react reversibly with CO2 molecules in membranes. This work provides a supramolecular approach to fabricating CO2 facilitated transport membranes.

  18. Identification of PADI2 as a potential breast cancer biomarker and therapeutic target

    International Nuclear Information System (INIS)

    We have recently reported that the expression of peptidylarginine deiminase 2 (PADI2) is regulated by EGF in mammary cancer cells and appears to play a role in the proliferation of normal mammary epithelium; however, the role of PADI2 in the pathogenesis of human breast cancer has yet to be investigated. Thus, the goals of this study were to examine whether PADI2 plays a role in mammary tumor progression, and whether the inhibition of PADI activity has anti-tumor effects. RNA-seq data from a collection of 57 breast cancer cell lines was queried for PADI2 levels, and correlations with known subtype and HER2/ERBB2 status were evaluated. To examine PADI2 expression levels during breast cancer progression, the cell lines from the MCF10AT model were used. The efficacy of the PADI inhibitor, Cl-amidine, was tested in vitro using MCF10DCIS cells grown in 2D-monolayers and 3D-spheroids, and in vivo using MCF10DCIS tumor xenografts. Treated MCF10DCIS cells were examined by flow-cytometry to determine the extent of apoptosis and by RT2 Profiler PCR Cell Cycle Array to detect alterations in cell cycle associated genes. We show by RNA-seq that PADI2 mRNA expression is highly correlated with HER2/ERBB2 (p = 2.2 × 106) in luminal breast cancer cell lines. Using the MCF10AT model of breast cancer progression, we then demonstrate that PADI2 expression increases during the transition of normal mammary epithelium to fully malignant breast carcinomas, with a strong peak of PADI2 expression and activity being observed in the MCF10DCIS cell line, which models human comedo-DCIS lesions. Next, we show that a PADI inhibitor, Cl-amidine, strongly suppresses the growth of MCF10DCIS monolayers and tumor spheroids in culture. We then carried out preclinical studies in nude (nu/nu) mice and found that Cl-amidine also suppressed the growth of xenografted MCF10DCIS tumors by more than 3-fold. Lastly, we performed cell cycle array analysis of Cl-amidine treated and control MCF10DCIS cells, and

  19. Synthesis of 2-(oxadiazolo, pyrimido, imidazolo, and benzimidazolo) substituted analogues of 1,4-benzodiazepin-5-carboxamides linked through a phenoxyl bridge

    Indian Academy of Sciences (India)

    N Kaur; D Kishore

    2014-11-01

    Exceedingly facile single-step expedient protocols based on the versatility and reactivity of corresponding intermediates amidine and imidate (8 and 9), derived from 5-carboxamido-1,4-benzodiazepin-5-(4'-methylpiperazinyl)-carboxamide have been developed to provide an easy installation of the oxadiazole, pyrimidine, imidazole and benzimidazole (9-14) based privileged templates at 2-position of 5-carboxamido-1,4-benzodiazepin-5-(4'-methylpiperazinyl)-carboxamide (4), through a phenoxyl spacer, by utilizing the synthetic strategy depicted in schemes 1 and 2.

  20. Structure-based design and synthesis of pyrazinones containing novel P1 'side pocket' moieties as inhibitors of TF/VIIa.

    Science.gov (United States)

    Schweitzer, Barbara A; Neumann, William L; Rahman, Hayat K; Kusturin, Carrie L; Sample, Kirby R; Poda, Gennadiy I; Kurumbail, Ravi G; Stevens, Anna M; Stegeman, Roderick A; Stallings, William C; South, Michael S

    2005-06-15

    We describe the structure-based design, synthesis, and enzymatic activity of a series of substituted pyrazinones as inhibitors of the TF/VIIa complex. These inhibitors contain substituents meta to the P(1) amidine designed to explore additional interactions with the VIIa residues in the so-called 'S(1) side pocket'. A crystal structure of the designed inhibitors demonstrates the ability of the P(1) side pocket moiety to engage Lys192 and main chain of Gly216 via hydrogen bond interactions, thus, providing additional possibility for chemical modification to improve selectivity and/or physical properties of inhibitors.

  1. N-terminal guanidinylation of TIPP (Tyr-Tic-Phe-Phe) peptides results in major changes of the opioid activity profile

    OpenAIRE

    Weltrowska, Grazyna; Nguyen, Thi M.-D.; Chung, Nga N.; Wilkes, Brian C.; Schiller, Peter W.

    2013-01-01

    Derivatives of peptides of the TIPP (Tyr-Tic-Phe-Phe; Tic = 1,2,3,4- tetrahydroisoquinoline-3-carboxylic acid) family containing a guanidino (Guan) function in place of the N-terminal amino group were synthesized in an effort to improve their blood-brain barrier permeability. Unexpectedly, N-terminal amidination significantly altered the in vitro opioid activity profiles. Guan-analogues of TIPP-related δ opioid antagonists showed δ partial agonist or mixed δ partial agonist/μ partial agonist ...

  2. Tuning of the Electronic Levels of Oligothiophene-Naphthalimide Assemblies by Chemical Modification.

    Science.gov (United States)

    de la Peña, Alejandro; Arrechea-Marcos, Iratxe; Mancheño, María J; Ruiz Delgado, M Carmen; López Navarrete, J Teodomiro; Segura, José L; Ponce Ortiz, Rocío

    2016-09-12

    Inversion of the connections of amidine linkers combined with controlled oligothiophene chain catenation in oligothiophene-naphthalimide assemblies provides an efficient method to tune the HOMO and LUMO values in this type of assemblies. This modification also suppresses the intramolecular charge transfer (ICT) band normally found in this type of derivatives, also delocalizing the frontier molecular orbitals over the whole conjugated skeleton. The resultant assemblies were used in the fabrication of field-effect transistors, which showed well-balanced ambipolar transport. PMID:27430480

  3. Multicomponent Synthesis of 3,6-Dihydro-2H-1,3-thiazine-2-thiones

    Directory of Open Access Journals (Sweden)

    Frans J. J. de Kanter

    2012-02-01

    Full Text Available Non-fused 3,6-dihydro-2H-1,3-thiazine-2-thiones constitute a so far rather unexplored class of compounds, with the latest report dating back more than two decades. Thiazine-2-thiones contain an endocyclic dithiocarbamate group, which is often found in pesticides, in substrates for radical chemistry and in synthetic intermediates towards thioureas and amidines. We now report the multicomponent reaction (MCR of in situ-generated 1-azadienes with carbon disulfide. With this reaction, a one-step protocol towards the potentially interesting 3,6-dihydro-2H-1,3-thiazine-2-thiones was established and a small library was synthesized.

  4. Synthesis, characterization and application of new azo dyes derived from uracil for polyester fibre dyeing

    Science.gov (United States)

    Yazdanbakhsh, Mohamad-reza; Abbasnia, Masoumeh; Sheykhan, Mehdi; Ma'mani, Leila

    2010-08-01

    Some novel uracil derived azo compounds were synthesized by diazotization of substituted aromatic amines, amidine- and guanidine-like amines such as 2-aminopyridine and 2-aminopyrimidine, ortho-hydroxy aniline and ortho-hydroxy naphthyl amines and coupling reaction with 6-amino-1,3-dimethyluracil. Structures of the dyes were fully characterized by spectroscopic techniques (UV, 1H NMR, 13C NMR, CHN and IR). The dyes were applied to polyester, affording orange-yellow shades and the wash fastness of the dyeings was excellent.

  5. Assessment of flavaglines as potential chikungunya virus entry inhibitors.

    Science.gov (United States)

    Wintachai, Phitchayapak; Thuaud, Frédéric; Basmadjian, Christine; Roytrakul, Sittiruk; Ubol, Sukathida; Désaubry, Laurent; Smith, Duncan R

    2015-03-01

    Chikungunya virus (CHIKV) is a re-emerging mosquito-borne alphavirus that recently caused large epidemics in islands in, and countries around, the Indian Ocean. There is currently no specific drug for therapeutic treatment or for use as a prophylactic agent against infection and no commercially available vaccine. Prohibitin has been identified as a receptor protein used by chikungunya virus to enter mammalian cells. Recently, synthetic sulfonyl amidines and flavaglines (FLs), a class of naturally occurring plant compounds with potent anti-cancer and cytoprotective and neuroprotective activities, have been shown to interact directly with prohibitin. This study therefore sought to determine whether three prohibitin ligands (sulfonyl amidine 1 m and the flavaglines FL3 and FL23) were able to inhibit CHIKV infection of mammalian Hek293T/17 cells. All three compounds inhibited infection and reduced virus production when cells were treated before infection but not when added after infection. Pretreatment of cells for only 15 minutes prior to infection followed by washing out of the compound resulted in significant inhibition of entry and virus production. These results suggest that further investigation of prohibitin ligands as potential Chikungunya virus entry inhibitors is warranted.

  6. Research Progress on Synthesis of Thrombin Inhibitor Dabigatran Etexilate%凝血酶抑制剂达比加群酯的合成进展

    Institute of Scientific and Technical Information of China (English)

    孙丽丽; 张瑶; 高虎

    2016-01-01

    Dabigatran etexilate is a novel thrombin inhibitor and used for preventing acute venous thrombosis, which has broad market prospects. The compound is mainly synthesized from 4-chloro-3-nitrobenzoic acid by amination, acylchlorination, acylamidation, hydrogenation, cyclization, amidination and acylation. The researches focus on optimizing the reaction conditions of hydrogenation, cyclization and amidination in the field of synthesis of the compound. The main synthetic methods of dabigatran etexilate were summarized.%达比加群酯是一种新型凝血酶抑制剂,用于预防急性静脉血栓,具有广阔的市场前景。目前主要以3-硝基-4-氯苯甲酸为起始原料,经氨化、酰氯化、酰胺化、氢化、环化、成脒、酰化制备该化合物。其中,氢化、环化、成脒反应条件的优化是该化合物合成领域的研究重点。本文对目前达比加群酯的主要合成方法进行了综述。

  7. Evaluation of the Efficacy of Acaricides Used to Control the Cattle Tick, Rhipicephalus microplus, in Dairy Herds Raised in the Brazilian Southwestern Amazon

    Directory of Open Access Journals (Sweden)

    Luciana G. Brito

    2011-01-01

    Full Text Available The adult immersion test (AIT was used to evaluate the efficacy of acaricide molecules used for control of Rhipicephalus microplus on 106 populations collected in five municipalities in the state of Rondônia in the Brazilian South Occidental Amazon region. The analysis of the data showed that the acaricide formulations had different efficacies on the tick populations surveyed. The synthetic pyrethroids (SPs acaricides were the least effective (48.35–76.84%, followed by SP + organophosphate (OP associations (68.91–81.47% and amidine (51.35–100%. For the macrocyclic lactones (MLs, the milbemycin (94.84–100% was the most effective, followed by spinosad (93.21–100% and the avermectins (81.34–100%. The phenylpyrazole (PZ group had similar efficacy (99.90% to the MLs. Therefore, SP acaricides, including associations with OP, and formulations based on amidine presented low in vitro efficacy to control the R. microplus populations surveyed.

  8. Design, synthesis and biological evaluation of PSMA/hepsin-targeted heterobivalent ligands.

    Science.gov (United States)

    Subedi, Milan; Minn, Il; Chen, Jianbo; Kim, YunHye; Ok, Kiwon; Jung, Yong Woo; Pomper, Martin G; Byun, Youngjoo

    2016-08-01

    Cell surface biomarkers such as prostate-specific membrane antigen (PSMA) and hepsin have received considerable attention as targets for imaging prostate cancer (PCa) due to their high cell surface expression in such tumors and easy access for imaging probes. Novel amidine-containing indole analogs (13-21) as hepsin inhibitors were designed and synthesized. These compounds showed in vitro inhibitory activity against hepsin with IC50 values from 5.9 to 70 μM. Based on the SAR of amidine-derived analogs, the novel heterobivalent compound 30, targeting both hepsin and PSMA, was synthesized by linking compound 18 with Lys-urea-Glu, the key scaffold for the specific binding to PSMA, followed by the conjugation of the optical dye SulfoCy7. Compound 30 exhibited inhibitory activities against PSMA and hepsin, with IC50 values of 28 nM and 2.8 μM, respectively. In vitro cell uptake and preliminary in vivo optical imaging studies of 30 showed selective binding and retention in both PSMA and hepsin high-expressing PC3/ML-PSMA-HPN cells as compared with low-expressing PC3/ML cells. PMID:27128184

  9. Surprisingly Different Reaction Behavior of Alkali and Alkaline Earth Metal Bis(trimethylsilyl)amides toward Bulky N-(2-Pyridylethyl)-N'-(2,6-diisopropylphenyl)pivalamidine.

    Science.gov (United States)

    Kalden, Diana; Oberheide, Ansgar; Loh, Claas; Görls, Helmar; Krieck, Sven; Westerhausen, Matthias

    2016-07-25

    N-(2,6-Diisopropylphenyl)-N'-(2-pyridylethyl)pivalamidine (Dipp-N=C(tBu)-N(H)-C2 H4 -Py) (1), reacts with metalation reagents of lithium, magnesium, calcium, and strontium to give the corresponding pivalamidinates [(tmeda)Li{Dipp-N=C(tBu)-N-C2 H4 -Py}] (6), [Mg{Dipp-N=C(tBu)-N-C2 H4 -Py}2 ] (3), and heteroleptic [{(Me3 Si)2 N}Ae{Dipp-N=C(tBu)-N-C2 H4 -Py}], with Ae being Ca (2 a) and Sr (2 b). In contrast to this straightforward deprotonation of the amidine units, the reaction of 1 with the bis(trimethylsilyl)amides of sodium or potassium unexpectedly leads to a β-metalation and an immediate deamidation reaction yielding [(thf)2 Na{Dipp-N=C(tBu)-N(H)}] (4 a) or [(thf)2 K{Dipp-N=C(tBu)-N(H)}] (4 b), respectively, as well as 2-vinylpyridine in both cases. The lithium derivative shows a similar reaction behavior to the alkaline earth metal congeners, underlining the diagonal relationship in the periodic table. Protonation of 4 a or the metathesis reaction of 4 b with CaI2 in tetrahydrofuran yields N-(2,6-diisopropylphenyl)pivalamidine (Dipp-N=C(tBu)-NH2 ) (5), or [(thf)4 Ca{Dipp-N=C(tBu)-N(H)}2 ] (7), respectively. The reaction of AN(SiMe3 )2 (A=Na, K) with less bulky formamidine Dipp-N=C(H)-N(H)-C2 H4 -Py (8) leads to deprotonation of the amidine functionality, and [(thf)Na{Dipp-N=C(H)-N-C2 H4 -Py}]2 (9 a) or [(thf)K{Dipp-N=C(H)-N-C2 H4 -Py}]2 (9 b), respectively, are isolated as dinuclear complexes. From these experiments it is obvious, that β-metalation/deamidation of N-(2-pyridylethyl)amidines requires bases with soft metal ions and also steric pressure. The isomeric forms of all compounds are verified by single-crystal X-ray structure analysis and are maintained in solution. PMID:27355970

  10. Investigação eletroquímica e calorimétrica da interação de novos agentes antitumorais biscatiônicos com DNA

    Directory of Open Access Journals (Sweden)

    Láuris Lucia da Silva

    2012-01-01

    Full Text Available Biscationic amidines bind in the DNA minor groove and present biological activity against a range of infectious diseases. Two new biscationic compounds (bis-α,ω-S-thioureido, amino and sulfide analogues were synthesized in good yields and fully characterized, and their interaction with DNA was also investigated. Isothermal titration calorimetry (ITC was used to measure the thermodynamic properties of binding interactions between DNA and these ligands. A double stranded calf thymus DNA immobilized on an electrode surface was used to study the possible DNA-interacting abilities of these compounds towards dsDNA in situ. A remarkable interaction of these compounds with DNA was demonstrated and their potential application as anticancer agents was furthered.

  11. 1,3-Dipolar cycloaddition reactivities of perfluorinated aryl azides with enamines and strained dipolarophiles.

    Science.gov (United States)

    Xie, Sheng; Lopez, Steven A; Ramström, Olof; Yan, Mingdi; Houk, K N

    2015-03-01

    The reactivities of enamines and predistorted (strained) dipolarophiles toward perfluoroaryl azides (PFAAs) were explored experimentally and computationally. Kinetic analyses indicate that PFAAs undergo (3 + 2) cycloadditions with enamines up to 4 orders of magnitude faster than phenyl azide reacts with these dipolarophiles. DFT calculations were used to identify the origin of this rate acceleration. Orbital interactions between the cycloaddends are larger due to the relatively low-lying LUMO of PFAAs. The triazolines resulting from PFAA-enamine cycloadditions rearrange to amidines at room temperature, while (3 + 2) cycloadditions of enamines and phenyl azide yield stable, isolable triazolines. The 1,3-dipolar cycloadditions of norbornene and DIBAC also show increased reactivity toward PFAAs over phenyl azide but are slower than enamine-azide cycloadditions. PMID:25553488

  12. Electrochemical and calorimetric investigation of interaction of novel biscationic anticancer agents with DNA; Investigacao eletroquimica e calorimetrica da interacao de novos agentes antitumorais biscationicos com DNA

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Lauris Lucia da; Donnici, Claudio Luis; Lopes, Julio Cesar Dias, E-mail: cdonnici@terra.com.br [Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil). Inst. de Ciencias Exatas. Dept. de Quimica; Goulart, Marilia Oliveira Fonseca; Abreu, Fabiane Caxico de; Paula, Francine Santos de [Universidade Federal de Alagoas (UFAL), Maceio, AL (Brazil). Campus A.C. Simoes. Inst. de Quimica e Biotecnologia; Bravo, Carlos E. Salas; Santoro, Marcelo Matos [Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil). Dept. de Bioquimica e Imunologia; Denadai, Angelo Marcio Leite [Centro Federal de Educacao Tecnologica, Timoteo, MG (Brazil). Campus VII; Santos, Alexandre Martins Costa [Universidade Federal do Espirito Santo, Vitoria, ES (Brazil). Dept. de Ciencias Fisiologicas; Montanari, Carlos Alberto [Universidade de Sao Paulo, Sao Carlos, SP (Brazil). Inst. de Quimica

    2012-07-01

    Biscationic amidines bind in the DNA minor groove and present biological activity against a range of infectious diseases. Two new biscationic compounds (bis-{alpha}-{omega}-S-thioureido, amino and sulfide analogues) were synthesized in good yields and fully characterized, and their interaction with DNA was also investigated. Isothermal titration calorimetry (ITC) was used to measure the thermodynamic properties of binding interactions between DNA and these ligands. A double stranded calf thymus DNA immobilized on an electrode surface was used to study the possible DNA-interacting abilities of these compounds towards dsDNA in situ. A remarkable interaction of these compounds with DNA was demonstrated and their potential application as anticancer agents was furthered. (author)

  13. Separation and quantitation of the polyamine biosynthesis inhibitor D,L-alpha-difluoromethylarginine and other guanidine-containing compounds by high-performance liquid chromatography.

    Science.gov (United States)

    Hunter, K J; Fairlamb, A H

    1990-11-01

    The arginine decarboxylase inhibitor difluoromethylarginine (DFMA) is an important tool in the study of polyamine metabolism, particularly with respect to the human pathogen Trypanosoma cruzi. This paper demonstrates a unique method for the detection and quantitation of intracellular DFMA using the fluorogenic agent 9,10-phenanthrenequinone. After separation of cell extracts by HPLC, DFMA can be accurately and reproducibly quantified with a lower sensitivity limit of 0.1 nmol by this simple fluorometric method. This assay can also be used to detect other guanidine-containing compounds such as arginine, agmatine, creatinine, and hirudonine, but not substituted guanidines such as aminoguanidine and creatine, or the structurally related amidines such as benzamidine and pentamidine.

  14. Antibacterial Drug Leads: DNA and Enzyme Multi-Targeting

    Science.gov (United States)

    Zhu, Wei; Wang, Yang; Li, Kai; Gao, Jian; Huang, Chun-Hsiang; Chen, Chun-Chi; Ko, Tzu-Ping; Zhang, Yonghui; Guo, Rey-Ting; Oldfield, Eric

    2015-01-01

    We report the results of an investigation of the activity of a series of amidine and bisamidine compounds against Staphylococcus aureus and Escherichia coli. The most active compounds bound to an AT-rich DNA dodecamer (CGCGAATTCGCG)2, and using DSC were found to increase the melting transition by up to 24 °C. Several compounds also inhibited undecaprenyl diphosphate synthase (UPPS) with IC50 values of 100–500 nM and we found good correlations (R2 = 0.89, S. aureus; R2 = 0.79, E. coli)) between experimental and predicted cell growth inhibition by using DNA ΔTm and UPPS IC50 experimental results together with 1 computed descriptor. We also solved the structures of three bisamidines binding to DNA as well as three UPPS structures. Overall, the results are of general interest in the context of the development of resistance-resistant antibiotics that involve multi-targeting. PMID:25574764

  15. Antibacterial drug leads: DNA and enzyme multitargeting.

    Science.gov (United States)

    Zhu, Wei; Wang, Yang; Li, Kai; Gao, Jian; Huang, Chun-Hsiang; Chen, Chun-Chi; Ko, Tzu-Ping; Zhang, Yonghui; Guo, Rey-Ting; Oldfield, Eric

    2015-02-12

    We report the results of an investigation of the activity of a series of amidine and bisamidine compounds against Staphylococcus aureus and Escherichia coli. The most active compounds bound to an AT-rich DNA dodecamer (CGCGAATTCGCG)2 and using DSC were found to increase the melting transition by up to 24 °C. Several compounds also inhibited undecaprenyl diphosphate synthase (UPPS) with IC50 values of 100-500 nM, and we found good correlations (R(2) = 0.89, S. aureus; R(2) = 0.79, E. coli) between experimental and predicted cell growth inhibition by using DNA ΔTm and UPPS IC50 experimental results together with one computed descriptor. We also solved the structures of three bisamidines binding to DNA as well as three UPPS structures. Overall, the results are of general interest in the context of the development of resistance-resistant antibiotics that involve multitargeting. PMID:25574764

  16. CO2 -Responsive polymers.

    Science.gov (United States)

    Lin, Shaojian; Theato, Patrick

    2013-07-25

    This Review focuses on the recent progress in the area of CO2 -responsive polymers and provides detailed descriptions of these existing examples. CO2 -responsive polymers can be categorized into three types based on their CO2 -responsive groups: amidine, amine, and carboxyl groups. Compared with traditional temperature, pH, or light stimuli-responsive polymers, CO2 -responsive polymers provide the advantage to use CO2 as a "green" trigger as well as to capture CO2 directly from air. In addition, the current challenges of CO2 -responsive polymers are discussed and the different solution methods are compared. Noteworthy, CO2 -responsive polymers are considered to have a prosperous future in various scientific areas.

  17. Synthesis and reactions with a midines of derivates cycles and of open chain of 2-bromo-3, 4-dioxobutanoic; Sintesis y reacciones con amidinas de derivados ciclicos y de cadena abierta del acido 2-bromo-3, 4-dioxobutanoico

    Energy Technology Data Exchange (ETDEWEB)

    Ancos, B. de; Delgado, F.; Martin, M.R. [Departamento de Quimica Organica, Facultad de Ciencias, Universidad Autonoma, Madrid (Spain)

    1995-12-31

    Bromination of enaminoesters 1 and 5, in appropriate conditions, affords in good yield enamines of the corresponding 2-bromo-3.4-dioxobutanoic acid derivatives 2-3 and 6 or dibromocompounds 4 and 6. The open chain enaminoesters (1-3) are more easily hydrolyzed that enaminofuranones 5 and 6. Prolongated treatment of 6 with hydrochloric acid affords the chlorinated enamine 11. The synthesis of 3-Bromo-4-hydroxy-5-methoxyfuran-2(5H)-one 10 can be achieved by bromination of 12, obtained by hydrolysis of 5. The reaction of methyl 3-bromo-4, 4-dimethoxy-3-oxobutanoate with amidines is a good method for the synthesis of 5-bromo-6-(dimethoxymethyl) pyrimidine-4(3H)-ones substituted at 2 position. Under the same conditions the reaction of furanone 10 with benzamide does not lead to the corresponding imidazoline. (Author) 12 refs.

  18. A straightforward and efficient synthesis of 3-(pyrimidinyl)propanoates from levulinic acid

    Energy Technology Data Exchange (ETDEWEB)

    Flores, Alex F.C.; Malavolta, Juliana L.; Souto, Alynne A.; Goularte, Rayane B.; Flores, Darlene C., E-mail: alex.fcf@ufsm.br [Universidade Federal de Santa Maria (UFSM/NUQUIMHE), RS (Brazil). Departamento de Quimica. Nucleo de Quimica de Heterociclos

    2013-04-15

    The cyclocondensation of methyl 7,7,7-trifluoro-4-methoxy-6-oxo-4-heptenoate and methyl 7,7,7-trichloro-4-methoxy-6-oxo-4-heptenoate, derived from levulinic acid with amidines [NH{sub 2}CONH{sub 2}, NH{sub 2}CR(NH) (R = H, Me, Ph, NH{sub 2}, SMe and 1H-pyrazol-1-yl), 5-amino-3-methyl-1H-pyrazol and 2-aminothiazole] into pyrimidine and pyrimidine-like derivatives as a new type of glutamate-like 3-(trihalomethylatedpyrimidinyl)propanoate is reported. Preparation of 3-(trihalomethylatedpyrimidinyl) propanohydrazides is also described. The synthetic potential of this straightforward protocol was established by the synthesis of fourteen new 3-(pyrimidinyl) propanoates in regular to good yields (38-92%). The structural assignments were based on the analysis of their {sup 1}H and {sup 13}C nuclear magnetic resonance (NMR) and gas chromatography-mass spectrometry (GC-MS) data. (author)

  19. Peptidylarginine deiminases: novel drug targets for prevention of neuronal damage following hypoxic ischemic insult (HI) in neonates.

    Science.gov (United States)

    Lange, Sigrun; Rocha-Ferreira, Eridan; Thei, Laura; Mawjee, Priyanka; Bennett, Kate; Thompson, Paul R; Subramanian, Venkataraman; Nicholas, Anthony P; Peebles, Donald; Hristova, Mariya; Raivich, Gennadij

    2014-08-01

    Neonatal hypoxic ischaemic (HI) injury frequently causes neural impairment in surviving infants. Our knowledge of the underlying molecular mechanisms is still limited. Protein deimination is a post-translational modification caused by Ca(+2) -regulated peptidylarginine deiminases (PADs), a group of five isozymes that display tissue-specific expression and different preference for target proteins. Protein deimination results in altered protein conformation and function of target proteins, and is associated with neurodegenerative diseases, gene regulation and autoimmunity. In this study, we used the neonatal HI and HI/infection [lipopolysaccharide (LPS) stimulation] murine models to investigate changes in protein deimination. Brains showed increases in deiminated proteins, cell death, activated microglia and neuronal loss in affected brain areas at 48 h after hypoxic ischaemic insult. Upon treatment with the pan-PAD inhibitor Cl-amidine, a significant reduction was seen in microglial activation, cell death and infarct size compared with control saline or LPS-treated animals. Deimination of histone 3, a target protein of the PAD4 isozyme, was increased in hippocampus and cortex specifically upon LPS stimulation and markedly reduced following Cl-amidine treatment. Here, we demonstrate a novel role for PAD enzymes in neural impairment in neonatal HI Encephalopathy, highlighting their role as promising new candidates for drug-directed intervention in neurotrauma. Hypoxic Ischaemic Insult (HI) results in activation of peptidylarginine deiminases (PADs) because of calcium dysregulation. Target proteins undergo irreversible changes of protein bound arginine to citrulline, resulting in protein misfolding. Infection in synergy with HI causes up-regulation of TNFα, nuclear translocation of PAD4 and change in gene regulation as a result of histone deimination. Pharmacological PAD inhibition significantly reduced HI brain damage.

  20. Anticancer, antioxidant activities, and DNA affinity of novel monocationic bithiophenes and analogues

    Directory of Open Access Journals (Sweden)

    Ismail MA

    2014-09-01

    Full Text Available Mohamed A Ismail,1,2 Reem K Arafa,3 Magdy M Youssef,1,2 Wael M El-Sayed1,4 1Departments of Chemistry and Biological Sciences, College of Science, King Faisal University, Hofuf, Saudi Arabia; 2Department of Chemistry, Faculty of Science, Mansoura University, Mansoura, Egypt; 3Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Cairo University, Cairo, Egypt; 4Department of Zoology, Faculty of Science, University of Ain Shams, Abbassia, Cairo, Egypt Abstract: A series of 15 monocationic bithiophenes and isosteres were prepared and subjected to in vitro antiproliferative screening using the full National Cancer Institute (NCI-60 cell line panel, representing nine types of cancer. Among the nine types of cancer involved in a five-dose screen, non-small cell lung and breast cancer cell lines were the most responsive to the antiproliferative effect of the tested compounds, especially cell lines A549/ATCC, NCI-H322M, and NCI-H460, whereas compounds 1a, 1c, 1d, and 7 exhibited potent activity, with GI50 values (drug concentration that causes 50% inhibition of cell growth from less than 10 nM to 102 nM. In addition, compounds 1c and 1d gave GI50 values of 73 nM and 79 nM, respectively, against the MDA-MB-468 breast cancer cell line. Structure–activity relationship findings indicated that the mononitriles were far less active than their corresponding monoamidines and, within the amidines series, the bioisosteric replacement of a thiophene ring by a furan led to a reduction in antiproliferative activity. Also, molecular manipulations, involving substitution on the phenyl ring, or its replacement by a pyridyl, or alteration of the position of the amidine group, led to significant alteration in antiproliferative activity. On the other hand, DNA studies demonstrated that these monoamidine bichalcophenes have promising ability to cleave the genomic DNA. These monoamidines show a wide range of DNA affinities, as judged from their DNA cleavage effect

  1. Amblyomma cajennense (Acari: Ixodidae) tick populations susceptible or resistant to acaricides in the Mexican Tropics.

    Science.gov (United States)

    Alonso-Díaz, M A; Fernández-Salas, A; Martínez-Ibáñez, F; Osorio-Miranda, J

    2013-10-18

    The objectives of the present study were: (i) to identify the frequency of cattle farms with a cohabitation of Amblyomma cajennense and Rhipicephalus microplus, (ii) to determine the status of susceptibility or resistance to acaricides used in Veracruz, Mexico, on A. cajennense populations and (iii) to identify factors associated with A. cajennense resistant to acaricides. Fifty farms were visited to determine the presence of ticks (A. cajennense and R. microplus) and to collect engorged A. cajennense individuals. From these, 24 A. cajennense populations were evaluated in resistance bioassays using discriminating doses of acaricides. The acaricides tested were organophosphates (chlorpiriphos, coumaphos and diazinon), pyrethroids (flumethrin, deltamethrin and cypermethrin), amidines (amitraz) and fipronil (a broad spectrum N-phenylpyrazole insecticide). A. cajennense infesting bovines were identified in 86% (43/50) of the farms visited, and 100% of the farms sampled (43/43) had cohabitation between R. microplus and A. cajennense. Of the farm owners or managers surveyed, 87.5% could not distinguish the morphological difference between tick genera. Populations of A. cajennense were 100%, 91.7% and 12.5% resistant to diazinon, coumaphos and chlorpyriphos (organophosphates), respectively, and 12.5% to amitraz, as were those susceptible to flumethrin and fipronil. In conclusions, populations of A. cajennense showed a high frequency of resistance to the organophosphates tested and to amitraz. Factors associated with the resistance to acaricides in A. cajennense were not identified. PMID:23827041

  2. Rhipicephalus (Boophilus) microplus in the western-central region of Rio Grande do Sul, Brazil: multiresistant tick.

    Science.gov (United States)

    Machado, Fabrício Amadori; Pivoto, Felipe Lamberti; Ferreira, Maiara Sanitá Tafner; Gregorio, Fabiano de Vargas; Vogel, Fernanda Silveira Flores; Sangioni, Luís Antônio

    2014-01-01

    The aim of the present study was to assess the acaricide resistance of tick populations in the western-central region of Rio Grande do Sul (Brazil), which has not previously been reported. Fifty-four cattle farms were visited and specimens of Rhipicephalus (Boophilus) microplus were collected and subjected to the adult immersion test, using nine commercial acaricides in the amidine, pyrethroid and organophosphate groups. Climatic data, including monthly precipitation, were recorded. The results from the present study demonstrated that seven of the acaricides analyzed presented mean efficacy values of less than 95%, with large differences among the products tested. Nine of them exhibited satisfactory and unsatisfactory acaricide results on at least one farm. In conclusion, the farms located in the western-central region of Rio Grande do Sul, Brazil, exhibited populations of R. (Boophilus) microplus with variable degrees of susceptibility to different acaricides, thus suggesting that resistance to the active compounds exists. It is suggested that treatment protocols should be implemented at the beginning of winter and summer, using the acaricides that showed efficacy in the adult immersion test. PMID:25271453

  3. Determination of acaricide resistance in Rhipicephalus (Boophilus) microplus (Acari: Ixodidae) field populations of Argentina, South Africa, and Australia with the Larval Tarsal Test.

    Science.gov (United States)

    Lovis, L; Reggi, J; Berggoetz, M; Betschart, B; Sager, H

    2013-03-01

    Infestations with ticks have an important economic impact on the cattle industry worldwide and resistance to acaricides has become a widespread phenomenon. To optimize their treatment strategy, farmers need to know if and against which classes potential acaricide-resistance does occur. Bioassays are used to assess the resistance level and pattern of Rhipicephalus (Boophilus) microplus populations. The objective of the current study was to assess the susceptibility of field populations originating from Argentina (8), South Africa (3), and Australia (2) using the Larval Tarsal Test. Nine acaricidal compounds from five major classes were tested: organosphosphates, synthetic pyrethroids (SP), macrocyclic lactones, phenylpyrazols, and amidines. The resistance ratios at concentrations inducing 50 and 90% mortality were used to detect established and emerging resistance. This study confirmed the newly reported presence of amitraz resistance in populations from Argentina In addition, resistance to SP appeared to be widespread (88%) in the Argentinean farms, which had been selected based on the observation of lack of treatment efficacy by farmers. In South Africa one of the three populations was found to be resistant to SP and to a phenylpyrazol compound (pyriprol). Furthermore, resistance to organosphosphates and SP was observed in Australia. Finally, the Larval Tarsal Test proved to be a suitable test to evaluate the susceptibility of R. microplus field populations to the most relevant acaricidal classes. PMID:23540121

  4. Effect of cell physicochemical characteristics and motility on bacterial transport in groundwater

    Science.gov (United States)

    Becker, M.W.; Collins, S.A.; Metge, D.W.; Harvey, R.W.; Shapiro, A.M.

    2004-01-01

    The influence of physicochemical characteristics and motility on bacterial transport in groundwater were examined in flow-through columns. Four strains of bacteria isolated from a crystalline rock groundwater system were investigated, with carboxylate-modified and amidine-modified latex microspheres and bromide as reference tracers. The bacterial isolates included a gram-positive rod (ML1), a gram-negative motile rod (ML2), a nonmotile mutant of ML2 (ML2m), and a gram-positive coccoid (ML3). Experiments were repeated at two flow velocities, in a glass column packed with glass beads, and in another packed with iron-oxyhydroxide coated glass beads. Bacteria breakthrough curves were interpreted using a transport equation that incorporates a sorption model from microscopic observation of bacterial deposition in flow-cell experiments. The model predicts that bacterial desorption rate will decrease exponentially with the amount of time the cell is attached to the solid surface. Desorption kinetics appeared to influence transport at the lower flow rate, but were not discernable at the higher flow rate. Iron-oxyhydroxide coatings had a lower-than-expected effect on bacterial breakthrough and no effect on the microsphere recovery in the column experiments. Cell wall type and shape also had minor effects on breakthrough. Motility tended to increase the adsorption rate, and decrease the desorption rate. The transport model predicts that at field scale, desorption rate kinetics may be important to the prediction of bacteria transport rates. ?? 2003 Elsevier B.V. All rights reserved.

  5. A Sustainable Multicomponent Pyrimidine Synthesis.

    Science.gov (United States)

    Deibl, Nicklas; Ament, Kevin; Kempe, Rhett

    2015-10-14

    Since alcohols are accessible from indigestible biomass (lignocellulose), the development of novel preferentially catalytic reactions in which alcohols are converted into important classes of fine chemicals is a central topic of sustainable synthesis. Multicomponent reactions are especially attractive in organic chemistry as they allow the synthesis of large libraries of diversely functionalized products in a short time when run in a combinatorial fashion. Herein, we report a novel, regioselective, iridium-catalyzed multicomponent synthesis of pyrimidines from amidines and up to three (different) alcohols. This reaction proceeds via a sequence of condensation and dehydrogenation steps which give rise to selective C-C and C-N bond formations. While the condensation steps deoxygenate the alcohol components, the dehydrogenations lead to aromatization. Two equiv of hydrogen and water are liberated in the course of the reactions. PN5P-Ir-pincer complexes, recently developed in our laboratory, catalyze this sustainable multicomponent process most efficiently. A total of 38 different pyrimidines were synthesized in isolated yields of up to 93%. Strong points of the new protocol are its regioselectivity and thus the immediate access to pyrimidines that are highly and unsymmetrically decorated with alkyl or aryl substituents. The combination of this novel protocol with established methods for converting alcohols to nitriles now allows to selectively assemble pyrimidines from four alcohol building blocks and 2 equiv of ammonia.

  6. N-terminal guanidinylation of TIPP (Tyr-Tic-Phe-Phe) peptides results in major changes of the opioid activity profile.

    Science.gov (United States)

    Weltrowska, Grazyna; Nguyen, Thi M-D; Chung, Nga N; Wilkes, Brian C; Schiller, Peter W

    2013-09-15

    Derivatives of peptides of the TIPP (Tyr-Tic-Phe-Phe; Tic=1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid) family containing a guanidino (Guan) function in place of the N-terminal amino group were synthesized in an effort to improve their blood-brain barrier permeability. Unexpectedly, N-terminal amidination significantly altered the in vitro opioid activity profiles. Guan-analogues of TIPP-related δ opioid antagonists showed δ partial agonist or mixed δ partial agonist/μ partial agonist activity. Guanidinylation of the mixed μ agonist/δ antagonists H-Dmt-Tic-Phe-Phe-NH2 (DIPP-NH2) and H-Dmt-TicΨ[CH2NH]Phe-Phe-NH2 (DIPP-NH2[Ψ]) converted them to mixed μ agonist/δ agonists. A docking study revealed distinct positioning of DIPP-NH2 and Guan-DIPP-NH2 in the δ receptor binding site. Lys(3)-analogues of DIPP-NH2 and DIPP-NH2[Ψ] (guanidinylated or non-guanidinylated) turned out to be mixed μ/κ agonists with δ antagonist-, δ partial agonist- or δ full agonist activity. Compounds with some of the observed mixed opioid activity profiles have therapeutic potential as analgesics with reduced side effects or for treatment of cocaine addiction. PMID:23932788

  7. In Vivo Nitric Oxide Synthase Inhibitors Can Be Deprived of This Activity: Unexpected Influence of the Tetrachloroplatinate(II) Counteranion. Crystal Structures of Bis(S-Methyl-Isothiouronium)-N,N'-Bis(3-Guanidinopropyl)Piperazinium and Hexamidinium Tetrachloroplatinates(II) Salts.

    Science.gov (United States)

    Morgant, G; Viossat, B; Roch-Arveiller, M; Prognon, P; Giroud, J P; Lancelot, J C; Robba, M; Huy, D N

    1998-01-01

    The synthesis and crystal structures of bis(S-methylisothiouronium) (MSTUH)(+), N,N'-bis((3- guanidinopropyl)piperazinium (PipeC3GuaH4)(4+) and hexamidinium (HexaH2)(2+) tetrachloro platinate(ll) salts ( called hereafter PtMSTU, PtPipeC3Gua and PtHexa respectively ) were investigated. These compounds contain the "amidine" function ( - C(=NH)NH(2) ) in which the H atoms supplied by the acid have become attached to the imino group of each terminal amidino function. Moreover, in PtPipeC3Gua, the nitrogen atoms of the chair-piperazine moiety are also protonated. The influence of tetrachloroplatinate(ll) counteranion ( versus sulfate, nitrate and diisethionate ) in the in vivo nitrite inhibition by the (MSTUH)(+), (PipeC3GuaH4)(4+) and (HexaH2)(2+) cations was investigated. The three tetrachloroplatinate(ll) salts, unexpectedly, do not inhibit significantly the in vivo nitrite production in comparison with the other salts (sulfate, nitrate and diisethionate and their corresponding previous countercations) which exhibit NO synthase inhibition, especially bis(S-methylisothiouronium) sulfate, a selective and potent inducible NO synthase (iNOS) inhibitor commonly used as standard. PMID:18475834

  8. Synthesis of Dabigatran Etexilate%达比加群酯的合成

    Institute of Scientific and Technical Information of China (English)

    程青芳; 王启发; 陆微; 黄芬芬; 陈娜

    2012-01-01

    Dabigatran etexilate was synthesized from 4-methylamino-3-nitrobenzoic acid (2) by acylchlorination and condensation with ethyl 3- (pyridin-2-ylamino) propanoate to give ethyl 3- [ (4-methylamino-3-nitrobenzoyl) (pyridin-2-yl) amino] propanoate, which was subjected to reduction by hydrazine in the presence of Fe-Al-Cu complex catalyst, amidation, cyclization, amidination and acylation with an overall yield of about 33.6% (based on 2).%4-甲胺基-3-硝基苯甲酸(2)经酰氯化后和3-(吡啶-2-基氨基)丙酸乙酯缩合,得3-[(4-甲胺基-3-硝基苯甲酰基)(吡啶-2-基)氨基]丙酸乙酯,再在Fe-Al-Cu复合催化剂作用下经水合肼还原、酰胺化后闭环、成脒及酰化反应等制得抗凝血药达比加群酯,总收率约33.6%(以2计).

  9. CO2-Responsive Polymer-Functionalized Au Nanoparticles for CO2 Sensor.

    Science.gov (United States)

    Ma, Ying; Promthaveepong, Kittithat; Li, Nan

    2016-08-16

    Metallic nanoparticles (NPs) coated with stimuli-responsive polymers (SRPs) exhibit tunable optical properties responding to external stimuli and show promising sensing applications. We present a new CO2-responsive polymer, poly(N-(3-amidino)-aniline) (PNAAN), coated gold NPs (AuNPs) synthesized by directly reducing HAuCl4 with a CO2-responsive monomer N-(3-amidino)-aniline (NAAN). The amidine group of PNAAN can be protonated into a hydrophilic amidinium group by dissolved CO2 (dCO2). This induces the PNAAN to swell and detach from the AuNP surface, resulting in AuNP aggregation and color change. By monitoring the UV absorbance change of AuNPs, a sensitive dCO2 sensor with a linear range of 0.0132 to 0.1584 hPa and a limit of detection (LOD) of 0.0024 hPa is developed. This method shows dramatic improvement in sensitivity and convenience of sample preparation compared with the previously reported dCO2 sensor.

  10. Fragment Binding Can Be Either More Enthalpy-Driven or Entropy-Driven: Crystal Structures and Residual Hydration Patterns Suggest Why.

    Science.gov (United States)

    Rühmann, Eggert; Betz, Michael; Heine, Andreas; Klebe, Gerhard

    2015-09-10

    In lead optimization, small, enthalpically advantaged fragments have been suggested to be superior, as an entropic component will be added inevitably during late-stage optimization. Determination of thermodynamic signatures of weak-binding fragments is essential to support the decision-making process, to decide which fragment to take to further optimization. High-resolution crystal structures of six fragments binding to the S1 pocket of thrombin were determined and analyzed with respect to their thermodynamic profile. The two most potent fragments exhibiting an amidine-type scaffold are not the most enthalpic binders; instead a chloro-thiophene fragment binds more enthalpically. Two chemically very similar chloro-aromatic fragments differ strongly in their potency (430 μM vs 10 mM); their binding modes are related, but the surrounding residual water network differs. The more potent one recruits a water molecule and involves Glu192 in binding, thus succeeding in firmly capping the S1 pocket. Fragments exhibiting a rather perfect solvation pattern in their binding mode also experience the highest potency.

  11. Simultaneous structure-activity studies and arming of natural products by C-H amination reveal cellular targets of eupalmerin acetate

    Science.gov (United States)

    Li, Jing; Cisar, Justin S.; Zhou, Cong-Ying; Vera, Brunilda; Williams, Howard; Rodríguez, Abimael D.; Cravatt, Benjamin F.; Romo, Daniel

    2013-06-01

    Natural products have a venerable history of, and enduring potential for the discovery of useful biological activity. To fully exploit this, the development of chemical methodology that can functionalize unique sites within these complex structures is highly desirable. Here, we describe the use of rhodium(II)-catalysed C-H amination reactions developed by Du Bois to carry out simultaneous structure-activity relationship studies and arming (alkynylation) of natural products at ‘unfunctionalized’ positions. Allylic and benzylic C-H bonds in the natural products undergo amination while olefins undergo aziridination, and tertiary amine-containing natural products are converted to amidines by a C-H amination-oxidation sequence or to hydrazine sulfamate zwitterions by an unusual N-amination. The alkynylated derivatives are ready for conversion into cellular probes that can be used for mechanism-of-action studies. Chemo- and site-selectivity was studied with a diverse library of natural products. For one of these—the marine-derived anticancer diterpene, eupalmerin acetate—quantitative proteome profiling led to the identification of several protein targets in HL-60 cells, suggesting a polypharmacological mode of action.

  12. Laccase-polyacrylonitrile nanofibrous membrane: highly immobilized, stable, reusable, and efficacious for 2,4,6-trichlorophenol removal.

    Science.gov (United States)

    Xu, Ran; Chi, Chenglong; Li, Fengting; Zhang, Bingru

    2013-12-11

    Increasing attention has been given to nanobiocatalysis for commercial applications. In this study, laccase was immobilized on polyacrylonitrile (PAN) nanofibrous membranes through ethanol/HCl method of amidination reaction and successfully applied for removal of 2,4,6-trichlorophenol (TCP) from water. PAN membranes with fiber diameters from 200 nm to 300 nm were fabricated via electrospinning and provided a large surface area for enzyme immobilization and catalytic reactions. Images of scanning electron microscope demonstrated the enzyme molecules were aggregated on the nanofiber surface. The immobilized laccase exhibited 72% of the free enzyme activity and kept 60% of its initial activity after 10 operation cycles. Moreover, the storage stability of the immobilized laccase was considered excellent because they maintained more than 92% of the initial activity after 18 days of storage, whereas the free laccase retained only 20%. The laccase-PAN nanofibrous membranes exhibited high removal efficiency of TCP under the combined actions of biodegradation and adsorption. More than 85% of the TCP was removed under optimum conditions. Effects of various factors on TCP removal efficiency of the immobilized laccase were analyzed. Results suggest that laccase-PAN nanofibrous membranes can be used in removing TCP from aqueous sources and have potential for use in other commercial applications. PMID:24245853

  13. STUDY ON THE SYNTHESIS OF POLYPERFLUOROTRIAZINE——The Synthesis and Polymerization of a Novel α,ω-Diiodoperfluorooxaalkyl s-Triazine Monomer

    Institute of Scientific and Technical Information of China (English)

    HUANG Weiyuan; HUANG Bingnan; HU Changming

    1983-01-01

    In order to investigate synthetic route of polyperfluorotriazine elastomer, 2-trifluoromethyl-4,6-bis(4'-iodo-2'-oxahexafluorobutyl)-1,3,5-triazine (1), a novel triazine monomer, was synthesized from 5-iodo-3-oxa-octafluoropentanesulfonyl fluoride (2) in eight-steps. 2 was reduced by potassium sulfite to the sulfinate (3), which was treated with hydriodic acid to yield 5-iodo-3-oxa-hexafluoropentanoic acid (4). Compound 4 was transformed to 5-iodo-3-oxa-hexafluoropentanenitrile (7) through the corresponding ester 5 and amide 6. The desired product 1 was prepared by acylation-cyclodehydration of the imidoylamidine 9, obtained by condensation of the nitrile 7with the amidine 8.The various methods for the esterification of perfluorocarboxylic acid were studied and a possible mechanism for the transformation of perfluorosulfinate to the corresponding perfluorocarboxylic acid by hydriodic acid was proposed.Crude 1 contained compounds 6, 11, 13, as impurities which were removed by low temperature crystallization followed by filtration through a short alumina column. The monomer 1 was polymerized by UV-irradiation in the presence of Hg with or without solvent. Polyperfluorooxaalkyl triazine 17 thus obtained showed good thermal stability. In the main chain of the polymer there was no weak unit of the uncyclized ring. Polymer 17 had an average molecular weight of ca.1.33-2.0×104 (D. P.=27-42) and the temperature of 10% weight loss in nitrogen was 340℃.

  14. 头孢硫脒治疗小儿急性扁桃体炎的临床观察

    Institute of Scientific and Technical Information of China (English)

    罗丹

    2014-01-01

    objective: to observe the sulfur analysis and physicochemical amidine clinical effect for the treatment of children with acute tonsillitis. Selection methods: our hospital in April 2012 to March 2013, the diagnosis and treatment of the clinical data of 62 cases of pediatric patients with acute tonsillitis, research analysis and patients randomly divided into treatment group (31 cases) and control group (31 cases), compared two groups of patients with therapeutic effect. Re-sults:compared two groups of patients with therapeutic effect, total effective rate of treatment group patients (93. 55%) significantly better than the control group pa-tients (67. 75%), with statistical significance (P < 0. 05);Appeared in the process of comparing two groups of patients allergic reaction rate, incidence of allergic reaction appeared in the process of the treatment group patients (6. 44%) was significantly lower than the control group patients (28. 98%), with statistical signifi-cance (P < 0. 05). Conclusion:the sulfur amidine in the treatment of infantile acute tonsillitis disease clinical effect is remarkable, which can effectively improve the clinical symptoms, improve patient quality of life, is worth popularization and application.%目的:观察分析头孢硫脒治疗小儿急性扁桃体炎的临床效果。方法:选取我院在2012年4月至2013年3月诊治的62例小儿急性扁桃体炎患者的临床资料进行研究分析,并随机将患者分为治疗组(31例)和对照组(31例),对比两组患者治疗效果。结果:对比两组患者治疗效果,治疗组患者治疗总有效率(93.55%)显著优于对照组患者的(67.75%),有统计学意义(P<0.05);对比两组患者治疗过程中出现过敏反应发生率,治疗组患者治疗过程中出现过敏反应发生率(6.44%)显著低于对照组患者的(28.98%),有统计学意义(P<0.05)。结论:头孢硫脒在治疗小儿急性扁桃体炎疾病临床上效果显著,可有效提高

  15. Polystyrene nanoparticle exposure induces ion-selective pores in lipid bilayers

    Science.gov (United States)

    Negoda, Alexander; Kim, Kwang-Jin; Crandall, Edward D.; Worden, Robert M.

    2014-01-01

    A diverse range of molecular interactions can occur between engineered nanomaterials (ENM) and biomembranes, some of which could lead to toxic outcomes following human exposure to ENM. In this study, we adapted electrophysiology methods to investigate the ability of 20 nm polystyrene nanoparticles (PNP) to induce pores in model bilayer lipid membranes (BLM) that mimic biomembranes. PNP charge was varied using PNP decorated with either positive (amidine) groups or negative (carboxyl) groups, and BLM charge was varied using dioleoyl phospholipids having cationic (ethylphosphocholine), zwitterionic (phosphocholine), or anionic (phosphatidic acid) headgroups. Both positive and negative PNP induced BLM pores for all lipid compositions studied, as evidenced by current spikes and integral conductance. Stable PNP-induced pores exhibited ion selectivity, with the highest selectivity for K+ (PK/PCl ~ 8.3) observed when both the PNP and lipids were negatively charged, and the highest selectivity for Cl− (PK/PCl ~ 0.2) observed when both the PNP and lipids were positively charged. This trend is consistent with the finding that selectivity for an ion in channel proteins is imparted by oppositely charged functional groups within the channel’s filter region. The PK/PCl value was unaffected by the voltage-ramp method, the pore conductance, or the side of the BLM to which the PNP were applied. These results demonstrate for the first time that PNP can induce ion-selective pores in BLM, and that the degree of ion selectivity is influenced synergistically by the charges of both the lipid headgroups and functional groups on the PNP. PMID:23747366

  16. Preparation and properties of pure acrylic polymer latex using novel emulsifying system%新型乳化体系下纯丙聚合物乳液的制备及性能研究

    Institute of Scientific and Technical Information of China (English)

    王太林; 何金国

    2015-01-01

    The acrylic polymer latex was successfully prepared via semi-continuous seeded emulsion polymerization, using methyl methacrylat (MMA) and butyl acrylate (BA)as the monomers monobutyl itaconate (MBI) as the functional monomer, mixture of tetradecyl dimethyl hydroxy propyl betaine and octylphenol polyoxyethylene ether(OP-10) as the emulsifier and 2,2'-azobis (2-methyl propion-amidine) dihydrochloride (V-50) as the initiator. The effects of the amounts of the emulsifiers, V-50 and MBI on the properties of the latex and its film were investigated. The results showed that the optimum conditions for preparing the latex were as follows: the amounts of emulsifier, V-50 and MBI were 7%, 0.5% and 4%,respectively.%采用半连续乳液聚合法,以甲基丙烯酸甲酯(MMA),丙烯酸正丁酯(BA)为主单体,衣康酸单丁酯(MBI)为功能性单体,偶氮二异丁脒盐酸盐(V-50)为引发剂,两性表面活性剂十四烷基二甲基羟丙基甜菜碱与烷基酚聚氧乙烯醚(O P-10)复配作为乳化剂,合成了丙烯酸酯乳液。分别探讨了乳化剂,V-50和MBI的用量对乳液及乳胶膜性能的影响。结果表明当乳化剂的用量占单体质量的7%,V-50为0.5%,MBI为4%时,乳液的综合性能最佳。

  17. Synthesis and radiofluorination of putative NMDA receptor ligands

    International Nuclear Information System (INIS)

    In the course of this work on the synthesis of radioligands for the NMDA receptor the authentic standards and labeling precursors of four compounds with an amidine structure was performed. Synthesis of the precursors followed reaction conditions given in the literature and was successful. The imidoesters used for the synthesis were obtained from their nitriles in a Pinner synthesis, while 2-hydroxybenzylamine was synthesized in a reduction of 2-hydroxybenzonitrile using borane as a reducing agent. After a coupling reaction of the amine and the imidoester in DMF using triethylamine as base the precursors were obtained in good yields and purified by crystallization from methanol. The cyclic standard compound was synthesized directly from 2-(bromomethyl)- benzonitrile and 2-hydroxybenzylamine in a ring closing reaction. Similar to the other precursors, crystallization from methanol produced a pure compound. The authentic standards were synthesized starting from salicylaldehyde. In a four step synthesis the desired ortho-fluoroethoxybenzylamine was obtained in good yield. Coupling of the amine with the respective imidoester or in the case of the cyclic compound 2-(bromomethyl)-benzonitrile gave the desired product which was then purified by column chromatography or by crystallization from ethanol and water. For the labeling procedure 1-bromo-2-[18F]fluoroethane was synthesized following a previously published pathway starting from 1,2-dibromoethane. An alternative route of radiosynthesis for this prosthetic group was tested using ethyleneglycole- 1,2-ditosylate. The labeling reaction was performed on one of the precursors testing both DMF and DMSO as solvents and using NaOH as base. Yields of N-(2-fluoroethoxybenzyl)- cinnamamidine were about 78 % at 80 C after 30 minutes in DMSO. The desired product can now be synthesized in sufficient yields for in vitro and in vivo evaluation studies. Labeling on the cyclic precursor was attempted utilizing DMSO as solvent, but no

  18. Stabilisation of carbonyl free amidinato-manganese(II) hydride complexes: "masked" sources of manganese(I) in organometallic synthesis.

    Science.gov (United States)

    Fohlmeister, Lea; Jones, Cameron

    2016-01-28

    Reaction of the amidinato-manganese(ii) bromide complex, [{(κ(2)-N,N'-Piso)Mn(μ-Br)}3(THF)2] (Piso = [(DipN)2CBu(t)](-), Dip = 2,6-diisopropylphenyl), with K[BHEt3] affords the first example of a structurally authenticated amidinato-manganese(ii) hydride complex, [{(N-,η(3)-arene-Piso)Mn(μ-H)2}2], via a process which involves a change in the amidinate coordination mode. Treatment of the bulkier precursor complex, [{(Piso'')Mn(μ-Br)}n] (Piso'' = [(Dip''N)2CBu(t)](-), Dip'' = C6H2Pr(i)2(CPh3)-2,6,4), with K[BHEt3] did not lead to an isolable manganese hydride complex, but its reaction with the magnesium(i) complex, [{((Mes)Nacnac)Mg}2] ((Mes)Nacnac = [(MesNCMe)2CH](-), Mes = mesityl), did. This reaction presumably proceeds via a reactive manganese(i) intermediate, which abstracts hydrogen from a reaction component to give [{(κ(2)-N,N'-Piso'')Mn(μ-H)}3]. A comparison of the reactivities of [{(N-,η(3)-arene-Piso)Mn(μ-H)2}2] and the isomorphous manganese(i) complex, [{(N-,η(3)-arene-Piso)Mn}2], toward CO, O2 and N2O was carried out. Reactions with the manganese(i) and manganese(ii) species gave identical results, namely the formation of the manganese(i) carbonyl complex, [(κ(2)-N,N'-Piso)Mn(CO)4] (reactions with CO), and the manganese(iii)-μ-oxo complex, [{(κ(2)-N,N'-Piso)Mn(μ-O)}2] (reactions with O2 and N2O). These results indicate that [{(N-,η(3)-arene-Piso)Mn(μ-H)2}2] can act as a "masked" source of an amidinato-manganese(i) fragment in synthetic transformations. PMID:26674008

  19. Imidate-Based Cross-Linkers for Structural Proteomics: Increased Charge of Protein and Peptide Ions and CID and ECD Fragmentation Studies

    Science.gov (United States)

    Koolen, Hector H. F.; Gomes, Alexandre F.; Schwab, Nicolas V.; Eberlin, Marcos N.; Gozzo, Fabio C.

    2014-07-01

    Chemical cross-linking is an attractive low-resolution technique for structural studies of protein complexes. Distance constraints obtained from cross-linked peptides identified by mass spectrometry (MS) are used to construct and validate protein models. Amidinating cross-linkers such as diethyl suberthioimidate (DEST) have been used successfully in chemical cross-linking experiments. In this work, the application of a commercial diimidate cross-linking reagent, dimethyl suberimidate (DMS), was evaluated with model peptides and proteins. The peptides were designed with acetylated N-termini followed by random sequences containing two Lys residues separated by an Arg residue. After cross-linking reactions, intra- and intermolecular cross-linked species were submitted to CID and ECD dissociations to study their fragmentation features in the gas phase. Fragmentation of intramolecular peptides by collision induced dissociation (CID) demonstrates a unique two-step fragmentation pathway involving formation of a ketimine as intermediate. Electron capture and electron transfer dissociation (ECD and ETD) experiments demonstrated that the cyclic moiety is not dissociated. Intermolecular species demonstrated previously described fragmentation behavior in both CID and ECD experiments. The charge state distributions (CSD) obtained after reaction with DMS were compared with those obtained with disuccinimidyl suberate (DSS). CSDs for peptides and proteins were increased after their reaction with DMS, owing to the higher basicity of DMS modified species. These features were also observed in LC-MS experiments with bovine carbonic anhydrase II (BCA) after cross-linking with DMS and tryptic proteolysis. Cross-linked peptides derived from this protein were identified at high confidence and those species were in agreement with the crystal structure of BCA.

  20. Antithrombotic effects of LB30870, a potent, orally active, selective and direct thrombin inhibitor, and pharmacokinetics of its prodrug.

    Science.gov (United States)

    Park, Hee Dong; Lee, Sung-Hack; Kim, Tae Hoon; Lee, Sun Hwa; Cho, Kwan Hyung; Kim, Aeri

    2013-09-01

    Antithrombotic activity and bleeding complication of a new potent, selective, and direct thrombin inhibitor, LB30870, were evaluated in comparison with other anticoagulants. In order to improve oral absorption of LB30870, pharmacokinetics of LB30889, which is a double prodrug with blocking groups in both amidine and carboxyl groups, was studied in rats and dogs. LB30870 was more potent than melagatran or argatroban with thrombin inhibition constants of 0.02, 1.3 and 4.5 nM, respectively. All three direct thrombin inhibitors were selective towards other serine proteases with selectivity ratio greater than 1000, except for trypsin. Thrombin binding kinetics of LB30870 showed rapid association and slow dissociation rate constants, demonstrating its potential as anticoagulant. LB30870 was more effective than melagatran or argatroban in plasma clot-bound thrombin inhibition. In the rat venous stasis model of the caval vein, LB30870 reduced wet clot weights in a dose dependent manner after the intravenous bolus with infusion administration. The ED50 of LB30870, melagatran and enoxaparin were 50 μg/kg+2 μg/kg/min, 35 μg/kg+1.4 μg/kg/min and 200 μg/kg+8.3 μg/kg/min, respectively. No significant bleeding problem was observed with LB30870 at the dose up to two times ED80 in rats. LB30889, a double prodrug of LB30870, showed species difference in pharmacokinetics. Its oral bioavailability in rats or dogs was not better than that of LB30870. In conclusion, LB30870 has the potential to be useful as an effective oral anticoagulant for the prevention and treatment of thromboembolic diseases. PMID:23899618

  1. 达比加群酯的合成工艺研究%Synthesis of dabigatran etexilate

    Institute of Scientific and Technical Information of China (English)

    高航; 宗新杰; 刘长鹰; 张海枝; 李川; 徐为人; 陈会慧

    2014-01-01

    目的:对达比加群酯的合成工艺进行研究。方法以3-[[[2-[[(4-氰基苯基)氨基]甲基]-1-甲基-1H-苯并咪唑-5-基]羰基](吡啶-2-基)氨基]丙酸乙酯为起始原料,经改进后的Pinner反应得到脒,再与氯甲酸正己酯反应得到达比加群酯。结果合成了目标化合物,并利用MS和1H-NMR确证了结构;收率为38.8%,质量分数为99.6%。结论该合成工艺简化了操作,设计合理,终产物达比加群酯收率及纯度较高,具备工业化可行性。%Objective To study the synthetic technology of dabigatran etexilate. Methods 3-[[[2-[[(4-Cyanophenyl)amino]methyl]-1-methyl-1H-benzimidazol-5-yl]carbonyl] pyridin-2-ylamino]propionic acid ethyl ester was used as starting material to synthesize amidine by Pinner reaction, then to obtain target compound by reacting with hexyl chloroformate. Results The target compound was synthesized and characterized by MS and 1H-NMR. The yield was 38.8%and the purity was 99.6%. Conclusion The synthetic route of dabigatran etexilate has the advantages of simple operation and reasonable design with high yield and purity, and is suitable for industrial production.

  2. Selectivity in ligand binding to uranyl compounds: A synthetic, structural, thermodynamic and computational study

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, John [Univ. of California, Berkeley, CA (United States)

    2015-01-21

    The uranyl cation (UO₂²⁺) is the most abundant form of uranium on the planet. It is estimated that 4.5 billion tons of uranium in this form exist in sea water. The ability to bind and extract the uranyl cation from aqueous solution while separating it from other elements would provide a limitless source of nuclear fuel. A large body of research concerns the selective recognition and extraction of uranyl. A stable molecule, the cation has a linear O=U=O geometry. The short U-O bonds (1.78 Å) arise from the combination of uranium 5f/6d and oxygen 2p orbitals. Due to the oxygen moieties being multiply bonded, these sites were not thought to be basic enough for Lewis acidic coordination to be a viable approach to sequestration. The goal of this research is thus to broaden the coordination chemistry of the uranyl ion by studying new ligand systems via synthetic, structural, thermodynamic and computational methods. It is anticipated that this fundamental science will find use beyond actinide separation technologies in areas such as nuclear waste remediation and nuclear materials. The focus of this study is to synthesize uranyl complexes incorporating amidinate and guanidinate ligands. Both synthetic and computational methods are used to investigate novel equatorial ligand coordination and how this affects the basicity of the oxo ligands. Such an understanding will later apply to designing ligands incorporating functionalities that can bind uranyl both equatorially and axially for highly selective sequestration. Efficient and durable chromatography supports for lanthanide separation will be generated by (1) identifying robust peptoid-based ligands capable of binding different lanthanides with variable affinities, and (2) developing practical synthetic methods for the attachment of these ligands to Dowex ion exchange resins.

  3. The synthetic cationic lipid diC14 activates a sector of the Arabidopsis defence network requiring endogenous signalling components.

    Science.gov (United States)

    Cambiagno, Damián Alejandro; Lonez, Caroline; Ruysschaert, Jean-Marie; Alvarez, María Elena

    2015-12-01

    Natural and synthetic elicitors have contributed significantly to the study of plant immunity. Pathogen-derived proteins and carbohydrates that bind to immune receptors, allow the fine dissection of certain defence pathways. Lipids of a different nature that act as defence elicitors, have also been studied, but their specific effects have been less well characterized, and their receptors have not been identified. In animal cells, nanoliposomes of the synthetic cationic lipid 3-tetradecylamino-tert-butyl-N-tetradecylpropionamidine (diC14) activate the TLR4-dependent immune cascade. Here, we have investigated whether this lipid induces Arabidopsis defence responses. At the local level, diC14 activated early and late defence gene markers (FRK1, WRKY29, ICS1 and PR1), acting in a dose-dependent manner. This lipid induced the salicylic acid (SA)-dependent, but not jasmonic acid (JA)-dependent, pathway and protected plants against Pseudomonas syringae pv. tomato (Pst), but not Botrytis cinerea. diC14 was not toxic to plant or pathogen, and potentiated pathogen-induced callose deposition. At the systemic level, diC14 induced PR1 expression and conferred resistance against Pst. diC14-induced defence responses required the signalling protein EDS1, but not NDR1. Curiously, the lipid-induced defence gene expression was lower in the fls2/efr/cerk1 triple mutant, but still unchanged in the single mutants. The amidine headgroup and chain length were important for its activity. Given the robustness of the responses triggered by diC14, its specific action on a defence pathway and the requirement for well-known defence components, this synthetic lipid is emerging as a useful tool to investigate the initial events involved in plant innate immunity.

  4. Tracers development for the PET study of nicotinic receptors: [11C]-mecamylamine and [11C]-SIB 1553A. Tritium and carbon-11 radiolabelling of a serine proteinase inhibitor: the t-PAstop

    International Nuclear Information System (INIS)

    In order to develop radiotracers for the Positron Emission Tomography (PET), we labelled both the mecamylamine and SIB-1553A with carbon-11 to study the nicotinic cholinergic receptors (nAChRs). The radiosynthesis of [11C]-t-PAstop and the labelling with tritium of one analogue were realized for cerebral ischemia PET studies. The [11C]-mecamylamine, a non-competitive and non-selective nAChRs antagonist was synthesized in 45 min via a N-[11C]-methylation reaction. In the rat brain, the ex vivo studies showed no radio-metabolite 45 min after the injection of [11C]-mecamylamine. The uptake kinetics in the rat brain or in vivo by PET in the anesthetized baboon or in the conscious monkey, reached a plateau around 45-50 min after injection. However, the saturation or displacement experiments did not permit to exhibit nor a significant difference of labelling between the different cerebral regions nor a specific uptake. In consequence, the [11C]-mecamylamine was not an appropriate radioligand for nAChRs PET study. The labelling of [11C]-SIB 1553A, a selective agonist for the nicotinic β4 subunit, required the synthesis in 5 steps (56% overall yield) of precursor for the incorporation of carbon-11. The radiosynthesis was performed in 36 min by a N-[11C]-methylation reaction (yield: 75%). The [11C]-t-PAstop was obtained from [11C]-KCN with yields from 80 to 90%. For the first time with carbon-11, the formation of an amidine group was realized from a nitrile group. The labelling by isotopic exchange of hydrogen by tritium of the t-PAstop did not permit to obtain the [3H]-t-PAstop but a tritiated analogue. This compound will be used to study its vectorization by micro-encapsulation. (author)

  5. Synthesis and radiofluorination of putative NMDA receptor ligands

    Energy Technology Data Exchange (ETDEWEB)

    Kronenberg, U.

    2011-01-15

    In the course of this work on the synthesis of radioligands for the NMDA receptor the authentic standards and labeling precursors of four compounds with an amidine structure was performed. Synthesis of the precursors followed reaction conditions given in the literature and was successful. The imidoesters used for the synthesis were obtained from their nitriles in a Pinner synthesis, while 2-hydroxybenzylamine was synthesized in a reduction of 2-hydroxybenzonitrile using borane as a reducing agent. After a coupling reaction of the amine and the imidoester in DMF using triethylamine as base the precursors were obtained in good yields and purified by crystallization from methanol. The cyclic standard compound was synthesized directly from 2-(bromomethyl)- benzonitrile and 2-hydroxybenzylamine in a ring closing reaction. Similar to the other precursors, crystallization from methanol produced a pure compound. The authentic standards were synthesized starting from salicylaldehyde. In a four step synthesis the desired ortho-fluoroethoxybenzylamine was obtained in good yield. Coupling of the amine with the respective imidoester or in the case of the cyclic compound 2-(bromomethyl)-benzonitrile gave the desired product which was then purified by column chromatography or by crystallization from ethanol and water. For the labeling procedure 1-bromo-2-[{sub 18}F]fluoroethane was synthesized following a previously published pathway starting from 1,2-dibromoethane. An alternative route of radiosynthesis for this prosthetic group was tested using ethyleneglycole- 1,2-ditosylate. The labeling reaction was performed on one of the precursors testing both DMF and DMSO as solvents and using NaOH as base. Yields of N-(2-fluoroethoxybenzyl)- cinnamamidine were about 78 % at 80 C after 30 minutes in DMSO. The desired product can now be synthesized in sufficient yields for in vitro and in vivo evaluation studies. Labeling on the cyclic precursor was attempted utilizing DMSO as solvent

  6. Uncharged isocoumarin-based inhibitors of urokinase-type plasminogen activator

    Directory of Open Access Journals (Sweden)

    Deck Lorraine M

    2006-02-01

    Full Text Available Abstract Background Urokinase-type plasminogen activator (uPA plays a major role in extracellular proteolytic events associated with tumor cell growth, migration and angiogenesis. Consequently, uPA is an attractive target for the development of small molecule active site inhibitors. Most of the recent drug development programs aimed at nonpeptidic inhibitors targeted at uPA have focused on arginino mimetics containing amidine or guanidine functional groups attached to aromatic or heterocyclic scaffolds. There is a general problem of limited bioavailability of these charged inhibitors. In the present study, uPA inhibitors were designed on an isocoumarin scaffold containing uncharged substituents. Results 4-Chloro-3-alkoxyisocoumarins were synthesized in which the 3-alkoxy group contained a terminal bromine; these were compared with similar inhibitors that contained a charged terminal functional group. Additional variations included functional groups attached to the seven position of the isocoumarin scaffold. N- [3-(3-Bromopropoxy-4-chloro-1-oxo-1H-isochromen-7-yl]benzamide was identified as an uncharged lead inhibitor of uPA, Ki = 0.034 μM. Molecular modeling of human uPA with these uncharged inhibitors suggests that the bromine occupies the same position as positively charged arginino mimetic groups. Conclusion This study demonstrates that potent uncharged inhibitors of uPA can be developed based upon the isocoumarin scaffold. A tethered bromine in the three position and an aromatic group in the seven position are important contributors to binding. Although the aim was to develop compounds that act as mechanism-based inactivators, these inhibitors are competitive reversible inhibitors.

  7. Conjugation of organoruthenium(II) 3-(1H-benzimidazol-2-yl)pyrazolo[3,4-b]pyridines and indolo[3,2-d]benzazepines to recombinant human serum albumin: a strategy to enhance cytotoxicity in cancer cells.

    Science.gov (United States)

    Stepanenko, Iryna N; Casini, Angela; Edafe, Fabio; Novak, Maria S; Arion, Vladimir B; Dyson, Paul J; Jakupec, Michael A; Keppler, Bernhard K

    2011-12-19

    Following our strategy of coupling cyclin-dependent kinase (Cdk) inhibitors with organometallic moieties to improve their physicochemical properties and bioavailability, five organoruthenium complexes (1c-5c) of the general formula [RuCl(η(6)-arene)(L)]Cl have been synthesized in which the arene is 4-formylphenoxyacetyl-η(6)-benzylamide and L is a Cdk inhibitor [3-(1H-benzimidazol-2-yl)-1H-pyrazolo[3,4-b]pyridines (L1-L3) and indolo[3,2-d]benzazepines (L4 and L5)]. All of the compounds were characterized by spectroscopic and analytical methods. Upon prolonged standing (2-3 months) at room temperature, the dimethyl sulfoxide (DMSO) solutions of 1c and 2c(-HCl) afforded residues, which after recrystallization from EtOH and EtOH/H(2)O, respectively, were shown by X-ray diffraction to be cis,cis-[Ru(II)Cl(2)(DMSO)(2)(L1)]·H(2)O and mer-[Ru(II)Cl(DMSO)(3)(L2-H)]·H(2)O. Compound 5c, with a coordinated amidine unit, undergoes E/Z isomerization in solution. The antiproliferative activities and effects on the cell cycle of the new compounds were evaluated. Complexes 1c-5c are moderately cytotoxic to cancer cells (CH1, SW480, A549, A2780, and A2780cisR cell lines). Therefore, in order to improve their antiproliferative effects, as well as their drug targeting and delivery to cancer cells, 1c-5c were conjugated to recombinant human serum albumin, potentially exploiting the so-called "enhanced permeability and retention" effect that results in the accumulation of macromolecules in tumors. Notably, a marked increase in cytotoxicity of the albumin conjugates was observed in all cases.

  8. Synthesis of dabigatran etexilate mesylate%甲磺酸达比加群酯的合成

    Institute of Scientific and Technical Information of China (English)

    程青芳; 王启发; 陆微; 黄芬芬; 秦亚娟

    2012-01-01

    Objective:To study and improve the synthesis proccess of dabigatran etexilate mesylate. Methods: The intermediate ethyl 3-[ [ 3-amino-4-( methylamino) benzoyl] ( pyridin-2-yl) amino]-propanoate (5) was prepared from 4-methyl amino-3-nitrobenzoic acid (2) and ethyl 3-( pyridin-2-ylamino) propanoate (3) by chlorination, amidation, neutralization and reduction. Dabigatran etexilate mesylate was synthesized from 5 and (4-cyanophenyl) glycine by amidation, cyclization, neutralization, amidination, acylation arid salification with methane sulfonic acid. Results; The structures of intermediates and target compound were identified by MS and H-NMR. The overall yield was 33. 9% . Conclusion; This improved method can be used in industrial manufacturing with the advantage of simpler purifying operation, lower cost and mild condition.%目的:研究和改进甲磺酸达比加群酯的合成工艺.方法:以4-甲氨基-3-硝基苯甲酸(2)和3-(吡啶-2-基氨基)丙酸乙酯(3)为原料,经酰氯化、酰胺化、中和成盐和还原制得重要中间体3-[ [3-氨基-4-(甲氨基)苯甲酰基](吡啶-2-基)氨基]丙酸乙酯(5).5再与N-(4-氰基苯基)甘氨酸经酰胺化、闭环、中和成盐、成脒、酰化,进而与甲磺酸成盐制得甲磺酸达比加群酯.结果:中间体及目标化合物经质谱、核磁共振谱、红外光谱等确证,整个工艺的总收率为33.9%.结论:本路线操作简便、成本较低、条件温和、步骤少,适合工业化生产.

  9. Avaliação in vitro da eficácia de acaricidas sobre Boophilus microplus (Canestrini, 1887 (Acari: Ixodidae de bovinos no município de Ilhéus, Bahia, Brasil In vitro valuation of acaricides efficiency to Boophilus microplus (Canestrini, 1887 (Acari: Ixodidae from bovines at the region of Ilhéus, Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Dunezeu Alves Campos Júnior

    2005-12-01

    were performed with engorged females of B. microplus collected from 30 farms randomly chosen in a group of 96 interviewed at the region. The current study showed the existence of resistance or sensibility of the populations of B. microplus to the contact acaricides commonly used at cattle properties of the region of Ilhéus. The four acaricides tested showed the following levels of efficiency: Amidin - 30.95%; Deltamethrin - 65.04%; Cipermethrin / diclorvos - 75.73%; and Triclorfon / coumaphos / cyfluthrin - 75.13%.

  10. 含氟丙烯酸酯乳液整理剂的合成及其在织物防水防油整理中的应用%Synthesis of fluoridated acrylic emulsion finishing agent and application in water and oil proofing finish on cotton fabric

    Institute of Scientific and Technical Information of China (English)

    何彦萱; 刘金华; 郭玉良; 刘军; 卢霜

    2014-01-01

    以甲基丙烯酸甲酯、丙烯酸异冰片酯、甲基丙烯酸十二烷基酯、六氟丙烯酸丁酯、二甲基丙烯酸丁二醇酯、3-氯-2-羟丙基甲基丙烯酸酯为单体,偶氮二异丁基脒盐酸盐为引发剂,合成阳离子含氟丙烯酸酯乳液,并应用于棉织物的拒水拒油整理.用红外光谱对聚合物进行表征,研究了交联剂对胶膜接触角及整理棉织物拒水拒油性能的影响.结果表明:未加交联剂,胶膜接触角达111.58°;加2%的三官能团氮丙啶交联剂,胶膜接触角可以提高到118.35°.经该乳液整理后的织物不仅具有较好的拒水性能,而且有突出的拒油性能,拒水达100分,拒油达6级;同时,耐久性良好,水洗30次以后,拒水为90分,拒油为5级.%Cationic fluorinated acrylic emulsions were synthesized with methyl methacrylate, isobornyl ac⁃rylate, lauryl methacrylate, hexafluorobutyl acrylate, butylene glycol dimethacrylate, 3- chloro- 2- hydroxypropyl methacrylate as monomers and azobis isobutyl amidine hydrochloride as the initiator, which was applied in wa⁃ter and oil repel ent finishing of cotton fabrics. The polymer emulsion properties were characterized with infra⁃red spectrometer. The effects of the crosslinking agent on the contact angle of the film and the water and oil repel ent properties of the finished fabrics were investigated. The results showed that the contact angle of the film was 111.58°, when 2% tri- functional aziridine crosslinking agent was added, the contact angle of the film was increased to 118.35°. The results showed that the finished fabric not only had good water repel ence but also had outstanding oil repel ence. The waterproofing level was 100 points, the oil repel ent level was grade 6; at the same time, the durability was excellent, after 30 times of washing, the waterproofing level was 90 points, and the oil repel ent level was grade 5.

  11. Suscetibilidade de Rhipicephalus (Boophilus microplus a carrapaticidas em Mato Grosso do Sul, Brasil Susceptibility of Rhipicephalus (Boophilus microplus to acaricides in Mato Grosso do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Alberto Gomes

    2011-08-01

    demonstrada aos distintos produtos testados sugere que a resistência do carrapato a diferentes classes esteja amplamente disseminada no Estado, motivo pelo qual recomenda-se a realização rotineira de testes de suscetibilidade antes da seleção e aplicação de produtos acaricidas para controle do carrapato.The cattle tick, Rhipicephalus (Boophilus microplus, is one of the most important ectoparasites of bovines, requiring adoption of control measures mainly in Bos taurus herds and its crossbreeds. Its control has becoming increasingly difficult due to selection of resistant populations by commercial products. This study aimed to know the status of cattle tick resistance to acaricides in the state of Mato Grosso do Sul. From October 2003 to October 2006 acaricide bioassays were conducted on cattle ticks from eleven of the most important livestock regions of the state. Adult immersion tests using regular commercial products according to label recommendations were followed by the evaluation of biological parameters. Twelve acaricide products containing one or more of seven active ingredients, from three chemical classes: amidine (amitraz, synthetic pyrethroid (cypermethrin, and organophosphates (chlorfenvinphos, chlorpyriphos, diazinon, dichlorvos, and ethion were tested. Low tick susceptibility was observed in all ranches, with several populations showing virtually no susceptibility to one or more products. Despite the great variation of susceptibility shown by the populations to each acaricide, a gradient of efficacy of these products was observed. Regardless of the acaricide class, the average efficacy of products containing a single active ingredient (19.94%-64.27% was generally lower than that showed by the mixtures, pyrethroid-organophosphate (46.38%-82.68% and between organophosphates (85.28%-97.68%. The mixture containing pyrethroid + OF + synergist + repellent (cypermethrin + chlorpyrifos + citronellal + piperonyl butoxide showed 100% efficacy, although it was

  12. Bulk gold catalyzed oxidation reactions of amines and isocyanides and iron porphyrin catalyzed N-H and O-H bond insertion/cyclization reactions of diamines and aminoalcohols

    Energy Technology Data Exchange (ETDEWEB)

    Klobukowski, Erik [Iowa State Univ., Ames, IA (United States)

    2011-01-01

    conditions, it was found that the oxidative dehydrogenation of dibenzylamine to Nbenzylidenebenzylamine, with N-methylmorpholine N-oxide (NMMO), was nearly quantitative (96%) within 24 h. However, the reaction with oxygen was much slower, with only a 52% yield of imine product over the same time period. Moreover, the rate of reaction was found to be influenced by the nature of the amine N-oxide. For example, the use of the weakly basic pyridine N-oxide (PyNO) led to an imine yield of only 6% after 24 h. A comparison of amine N-oxide and O2 was also examined in the oxidation of PhCH{sub 2}OH to PhCHO catalyzed by bulk gold. In this reaction, a 52% yield of the aldehyde was achieved when NMMO was used, while only a 7% product yield was afforded when O{sub 2} was the oxidant after 48 h. The bulk gold-catalyzed oxidative dehydrogenation of cyclic amines generates amidines, which upon treatment with Aerosil and water were found to undergo hydrolysis to produce lactams. Moreover, 5-, 6-, and 7-membered lactams could be prepared through a one-pot reaction of cyclic amines by treatment with oxygen, water, bulk gold, and Aerosil. This method is much more atom economical than industrial processes, does not require corrosive acids, and does not generate undesired byproducts. Additionally, the gold and Aerosil catalysts can be readily separated from the reaction mixture. The second project involved studying iron(III) tetraphenylporphyrin chloride, Fe(TPP)Cl, as a homogeneous catalyst for the generation of carbenes from diazo reagents and their reaction with heteroatom compounds. Fe(TPP)Cl, efficiently catalyzed the insertion of carbenes derived from methyl 2-phenyldiazoacetates into O-H bonds of aliphatic and aromatic alcohols. Fe(TPP)Cl was also found to be an effective catalyst for tandem N-H and O-H insertion/cyclization reactions when 1,2-diamines and 1,2-alcoholamines were treated with diazo reagents. This approach provides a one-pot process for synthesizing piperazinones and