Molecular characterisation of the NSP4 gene of group A human rotavirus G2P[4] strains circulating in São Paulo, Brazil, from 1994 and 2006 to 2010

Group A human rotaviruses (HuRVA) are causative agents of acute gastroenteritis. Six viral structural proteins (VPs) and six nonstructural proteins (NSPs) are produced in RV-infected cells. NSP4 is a diarrhoea-inducing viral enterotoxin and NSP4 gene analysis revealed at least 15 (E1-E15) genotypes. This study analysed the NSP4 genetic diversity of HuRVA G2P[4] strains collected in the state of São Paulo (SP) from 1994 and 2006-2010 using reverse transcription-polymerase chain reaction, sequencing and phylogenetic analysis. Forty (97.6%) G2P[4] strains displayed genotype E2; one strain (2.4%) displayed genotype E1. These results are consistent with the proposed linkage between VP4/VP7 (G2P[4]) and the NSP4 (E2) genotype of HuRVA. NSP4 phylogenetic analysis showed distinct clusters, with grouping of most strains by their genotype and collection year, and most strains from SP were clustered together with strains from other Brazilian states. A deduced amino acid sequence alignment for E2 showed many variations in the C-terminal region, including the VP4-binding domain. Considering the ability of NSP4 to generate host immunity, monitoring NSP4 variations, along with those in the VP4 or VP7 protein, is important for evaluating the circulation and pathogenesis of RV. Finally, the presence of one G2P[4]E1 strain reinforces the idea that new genotype combinations emerge through reassortment and independent segregation.

Optical characterization of sol-gel glasses derived from Eu3+ complex-forming precursors

Fabrication of new optical devices based upon the incorporation of rare earth ions via sol-gel methods depends on elimination of dopant ion clusters and residual hydroxyl groups from the final material. The optical absorption and/or luminescence properties of luminescent rare earth ions are influenced by the local bonding environment and the distribution of the rare-earth dopants in the matrix. Typically, dopants are incorporated into gel via dissolution of soluble species into the initial precursor sol. In this work, Eu3+ is used as optical probe, to assess changes in the local environment. Results of emission, excitation, fluorescence line narrowing and lifetimes studies of Eu3+-doped gels derived from Si(OCH3)4 and fluorinated/chelate Eu3+ precursors are presented. The precursors used in the sol-gel synthesis were: tris (6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionate) Eu(III), Eu (III) trifluoromethanesulfonate, Eu(III) acetylacetonate hydrate, Eu (III) trifluoroacetate trihidrate, tris (2,2,6,6-tetramethyl-3,5- heptanedionate) Eu(III) and Eu(NO3)3.6H2O. The results were interpreted in terms of the evolution of the Eu3+ fluorescence in systems varying from solution to the gels densified to 800ºC. The lifetimes studies indicate that the fluorinated precursors are effective at reducing the water content in densified gels.

Fotoquímica de chalconas fluoradas no estado sólido

Chalcone and its fluorinated derivatives were synthesized and photolyzed in the solid state. UV irradiation of chalcone and its monosubstituted fluorine derivatives (3- and 4-fluorchalcone) resulted in a mixture of anti-head-head (gamma-truxinic), sin-head-tail (alpha-truxilic) and anti-head-tail (epsilon-truxilic) dimers. On the other hand, upon irradiation of 3,4- and 3,5-difluorchalcone a stereoselective formation of the alpha-truxilic photodimer was observed, whereas for 2-substituted chalcones (2,3difluorchalcone, 2,5-difluorchalcone, 2,6-difluorchalcone and 2,3,4-trifluorchalcone) the beta-truxilic dimer was stereoselectively obtained. 2',3',4',5',6'-pentafluorchalcone was the less reactive of all chalcones studied and at least one of the possible photodimers, i.e the anti-head-head isomer, was identified. Irradiation of polyfluorinated chalcones such as 2,3,5,6-tetrafluor-, 2,3,4,5,6-pentafluor-, and 2,2',3,3',4,4',5,5',6,6'-decafluorchalcone led only to polymerization and/or decomposition products.

Métodos de obtenção, reatividade e importância biológica de 4-tiazolidinonas

Molecules containing the 4-thiazolidinone ring are known to possess a wide range of biological properties including antimicrobial and anti-inflammatory activities among others. These compounds can be synthesized by cyclization reactions involving alpha-haloacetic acid or alpha-mercaptoacetic acid and employed in several chemoselective reactions. Comprehensive reviews have been written on 4-thiazolidinones in 1961 by Brown and in 1980 by Singh et al. In the recent literature, some new synthesis methods for 4-thiazolidinone derivatives and several reactions have been reported. These advances warrant to review the chemical and biological properties of compounds with this important heterocycle employed in synthetic organic chemistry and medicinal chemistry.

Síntese e avaliação da atividade antimicrobiana de novas 4-tiazolidinonas obtidas a partir de formilpiridina tiossemicarbazonas

Twelve novel 4-thiazolidinone derivatives (2a-l) have been synthesized by reacting formilpyridine thiosemicarbazones (1a-l) and anhydride maleic in toluene. Their chemical structures were confirmed by IR, ¹H and 13C NMR. The new compounds were submitted to in vitro evaluation against pathogenic Gram-positive, Gram-negative bacteria and yeasts. The findings obtained showed that the compounds 2a, 2d, 2e and 2g were effective against some of the bacterial strains used, whereas the compounds 2d, 2e and 2i exhibited a moderate antifungal activity against the yeast strains evaluated. An initial structure activity relationship (SAR) was established.

Estudo fitoquímico da madeira de Guarea macrophylla (Meliaceae)

In the present work, the crude ethanol extract from wood of G. macrophylla was submitted to liquid/liquid partition between hexane, CH2Cl2, EtOAc and n-BuOH. Each phase was individually chromatographed over silica gel, Sephadex LH-20 or Amberlite XAD-2 to give eight terpene derivatives, such as five sesquiterpenoids (caryophyllene oxide, guai-6-en-10β-ol, spathulenol, aromadendrane-4β,10α-diol and aloaromadendrane-4α,10β-diol) as well as three triterpenoids (cicloart-24-ene-3β,23(R*)-diol, cicloart-24-ene-3β,23(S*)-diol, and cicloart-23E-ene-3β,25-diol). Additionally, were isolated three fatty acids (linolenic, linoleic and stearic), two steroids (sitosterol and stigmasterol) and sacarose. The structures of all these compounds were characterized by spectrometric analysis, mainly mass spectrometry and NMR and comparison of these data described in the literature.

Metabólitos secundários das esponjas Aplysina fistularis e Dysidea sp. e atividade antituberculose da 11-cetofistularina-3

The present investigation reports the isolation of aeroplysinin-2, 2-(3,5-dibromo-4-methoxyphenyl)-N,N,N-trimethyletanamonium, 7,9-dibromo-10-hydroxy-8-methoxy-1-oxa-2-azaspiro[4.5]deca-2,6,8-trien-3-carboxylic acid and its methyl ester, 11-oxoaerothionin, aerothionin, 11-keto-12-hydroxyaerothionin, 11-ketofistularin-3 and fistularin-3 from Aplysina fistularis, as well as of furodysinin lactone and 9α,11α-epoxicholest-7-en-3β,5α,6α,10-tetrol-6-acetate from Dysidea sp. Although the extracts of both sponges displayed antituberculosis activity, only 11-ketofistularin-3 isolated from A. fistularis displayed antimycobacterial activity against Mycobacterium tuberculosis H34Rv, with MIC at 16 μg/mL and SI of 40, a result that reinforce that fistularin-3 derivatives are interesting leads for the development of antituberculosis drugs.

Triagem de suportes orgânicos e protocolos de ativação na imobilização e estabilização de lipase de Thermomyces lanuginosus

Lipase from Thermomyces lanuginosus was covalently immobilized on activated poly-hydroxybutyrate, sugarcane bagasse and the chemically modified hybrid hydrogel chitosan-alginate prepared by different strategies. Among the tested supports, chitosan-alginate chemically modified with 2,4,6-trinitrobenzenesulfonic acid rendered derivatives with the highest hydrolytic activity and thermal-stability, 45-fold more stable than soluble lipase and was then selected for further studies. The pH of maximum activity was similar for both immobilized and free lipase (pH 8.0) while optimum temperature was 5 - 10 ºC higher for the immobilized lipase. Higher yields in the butyl butyrate synthesis were found for the derivatives prepared by activation with glycidol and epichlorohydrin.

Síntese de derivados 4-aril-3,4-di-hidrocumarínicos catalisada por NbCl5

Multicomponent reactions between phenols, β-diesters and benzaldehydes for the synthesis of 4-aryl-3,4-dihydrocoumarin derivatives were carried out under mild conditions (room temperature) and presented moderate yields (38-88%) and reasonable reaction times (2-4 days), using niobium pentachloride as a catalyst.

DI-HIDROCUCURBITACINA B: SEMI-SÍNTESE DE NOVOS DERIVADOS GLICOSILADOS

In the last ten years, the interest in natural and semi-synthetic cucurbitacin derivatives has increased, primarily due their cytotoxic and anti-tumoral activities. However, the isolation of glycosylated cucurbitacins has been difficult due the presence of β-glucosidase enzyme. With the aim of obtaining new glycosylated derivatives, the glycosylation of dihydrocucurbitacin B under Köenigs-Knorr and imidate reaction conditions was studied. Novel glycoside derivatives 16-(1,2-orthoacetate-3,4,6-tri-O-acetyl-α-D-glucopyranosyl)-dihydrocucurbitacin B (2), 2-O-β-D-2,3,4,6-tetra-O-acetyl-galactopyranosyl dihydrocucurbitacin B (3) and 2-O-β-D-galactopyranosyl dihydrocucurbitacin B (4) were synthesized for the first time in 17% (2 and 3) and 48% (4) yields.

2-(4-IODO-2,5-DIMETOXIFENIL)-N-[(2-METOXIFENIL)METIL]ETAMINA OU 25I-NBOME: CARACTERIZAÇÃO QUÍMICA DE UMA DESIGNER DRUG

Drug trafficking and the introduction of new drugs onto the illicit market are one of the main challenges of the forensic community. In this study, the chemical profile of a new designer drug, 2-(4-iodine-2,5-dimethoxyphenyl)-n-[(2-methoxyphenyl)methyl]etamine or 25I-NBOMe was explored using thin layer chromatography (TLC), ultraviolet-visible spectrophotometry (UV-Vis), attenuated total reflection with Fourier transform infrared spectroscopy(ATR-FTIR), gas chromatography mass spectrometry (GC-MS) and electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-ICR MS). First, the TLC technique was effective for identifying spots related to 25C-, 25B- and 25I-NBOMe compounds, all with the same retention factor, Rf ≈ 0.50. No spot was detected for 2,5-dimethoxy-4-bromoamphetamine, 2,5-Dimethoxy-4-chloroamphetamine or lysergic acid diethylamide compounds. ATR-FTIR preserved the physical-chemical properties of the material, whereas GC-MS and ESI-MS showed better analytical selectivity. ESI(+)FT-ICR MS was used to identify the exact mass (m/z428.1706 for the [M + H]+ ion), molecular formula (M = C18H22INO3), degree of unsaturation (DBE = 8) and the chemical structure (from collision induced dissociation, CID, experiments) of the 25I-NBOMe compound. Furthermore, the ATR-FTIR and CID results suggested the presence of isomers, where a second structure is proposed as an isomer of the 25I-NBOMe molecule.

Synthesis, spectroscopic characterization and antibacterial screening of novel n-(benzothiazol-2-yl)ethanamides

Synthesis, electronic, infrared, elemental micro analytical studies were carried on N-(benzothiazol-2-yl)trichloroethanamide [4] and N-(benzothiazol-2-yl)chloroethanamide [5]. They were also screened in vitro and in vivo for antibacterial activity. The results indicate that the compounds are very stable and that they show high antibacterial activities against both gram-positive and gram-negative bacteria tested. Both derivatives of 2-aminobenzothiazole were active against the multiresistant bacteria with IZD ranging from 9 -18 mm [5] and 9 - 20mm [4]. From the MIC results it is observed that the [5] derivative produced a better antibacterial activity than the [4] derivative. The lethal concentrations (LC50) of the compounds were also determined. Their solubilities and melting points were also determined.

Narrow-band 1, 2, 3, 4, 8, 16 and 24 cycles/360º angular frequency filters

We measured human frequency response functions for seven angular frequency filters whose test frequencies were centered at 1, 2, 3, 4, 8, 16 or 24 cycles/360º using a supra-threshold summation method. The seven functions of 17 experimental conditions each were measured nine times for five observers. For the arbitrarily selected filter phases, the maximum summation effect occurred at test frequency for filters at 1, 2, 3, 4 and 8 cycles/360º. For both 16 and 24 cycles/360º test frequencies, maximum summation occurred at the lower harmonics. These results allow us to conclude that there are narrow-band angular frequency filters operating somehow in the human visual system either through summation or inhibition of specific frequency ranges. Furthermore, as a general result, it appears that addition of higher angular frequencies to lower ones disturbs low angular frequency perception (i.e., 1, 2, 3 and 4 cycles/360º), whereas addition of lower harmonics to higher ones seems to improve detection of high angular frequency harmonics (i.e., 8, 16 and 24 cycles/360º). Finally, we discuss the possible involvement of coupled radial and angular frequency filters in face perception using an example where narrow-band low angular frequency filters could have a major role.

Dopaminergic profile of new heterocyclic N-phenylpiperazine derivatives

Dopamine constitutes about 80% of the content of central catecholamines and has a crucial role in the etiology of several neuropsychiatric disorders, including Parkinson's disease, depression and schizophrenia. Several dopaminergic drugs are used to treat these pathologies, but many problems are attributed to these therapies. Within this context, the search for new more efficient dopaminergic agents with less adverse effects represents a vast research field. The aim of the present study was to report the structural design of two N-phenylpiperazine derivatives, compound 4: 1-[1-(4-chlorophenyl)-1H-4-pyrazolylmethyl]-4-phenylhexahydropyrazine and compound 5: 1-[1-(4-chlorophenyl)-1H-1,2,3-triazol-4-ylmethyl]-4-phenylhexahydropyrazine, planned to be dopamine ligands, and their dopaminergic action profile. The two compounds were assayed (dose range of 15-40 mg/kg) in three experimental models: 1) blockade of amphetamine (30 mg/kg, ip)-induced stereotypy in rats; 2) the catalepsy test in mice, and 3) apomorphine (1 mg/kg, ip)-induced hypothermia in mice. Both derivatives induced cataleptic behavior (40 mg/kg, ip) and a hypothermic response (30 mg/kg, ip) which was not prevented by haloperidol (0.5 mg/kg, ip). Compound 5 (30 mg/kg, ip) also presented a synergistic hypothermic effect with apomorphine (1 mg/kg, ip). Only compound 4 (30 mg/kg, ip) significantly blocked the amphetamine-induced stereotypy in rats. The N-phenylpiperazine derivatives 4 and 5 seem to have a peculiar profile of action on dopaminergic functions. On the basis of the results of catalepsy and amphetamine-induced stereotypy, the compounds demonstrated an inhibitory effect on dopaminergic behaviors. However, their hypothermic effect is compatible with the stimulation of dopaminergic function which seems not to be mediated by D2/D3 receptors.

Simultaneous changes in the function and expression of beta 1 integrins during the growth arrest of poorly differentiated colorectal cells (LISP-1)

Cells usually lose adhesion and increase proliferation and migration during malignant transformation. Here, we studied how proliferation can affect the other two characteristics, which ultimately lead to invasion and metastasis. We determined the expression of ß1 integrins, as well as adhesion and migration towards laminin-1, fibronectin, collagens type I and type IV presented by LISP-1 colorectal cancer cells exposed to 2.5% dimethyl sulfoxide (DMSO), an agent capable of decreasing proliferation in this poorly differentiated colorectal cell line. Untreated cells (control), as shown by flow cytometry and monoclonal antibodies, expressed alpha2 (63.8 ± 11.3% positive cells), alpha3 (93.3 ± 7.0%), alpha5 (50.4 ± 12.0%) and alpha6 (34.1 ± 4.9%) integrins but not alpha1, alpha4, alphav or ß4. Cells adhered well to laminin-1 (73.4 ± 6.0%) and fibronectin (40.0 ± 2.0%) substrates but very little to collagens. By using blocking monoclonal antibodies, we showed that alpha2, alpha3 and alpha6 mediated laminin-1 adhesion, but neither alpha3 nor alpha5 contributed to fibronectin adherence. DMSO arrested cells at G0/G1 (control: 55.0 ± 2.4% vs DMSO: 70.7 ± 2.5%) while simultaneously reducing alpha5 (24.2 ± 19%) and alpha6 (14.3 ± 10.8%) expression as well as c-myc mRNA (7-fold), the latter shown by Northern blotting. Although the adhesion rate did not change after exposure to DMSO, alpha3 and alpha5 played a major role in laminin-1 and fibronectin adhesion, respectively. Migration towards laminin-1, which was clearly increased upon exposure to DMSO (control: 6 ± 2 cells vs DMSO: 64 ± 6 cells), was blocked by an antibody against alpha6. We conclude that the effects of DMSO on LISP-1 proliferation were accompanied by concurrent changes in the expression and function of integrins, consequently modulating adhesion/migration, and revealing a complex interplay between function/expression and the proliferative state of cells.