Synchrotron X-ray powder diffraction data of atorvastatin

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

AN IMPROVED ELECTROPHORETIC METHOD FOR THE DETERMINATION OF SERUM MILK PROTEIN VARIANTS IN GYR-HOLSTEIN COWS

Milk serum proteins such as alpha-lactalbumin (ALA) and beta-lactoglobulin (BLG) present biochemical polymorphism which is under the control of codominant autosomal alleles. In the present report, we propose modifications of traditional electrophoretic techniques such as increasing the running gel concentration from 5 to 10% and the addition of 5 M urea to the stacking gel, which permitted the detection of two variants (A and B) at the ALA and BLG loci. About 8 mul of milk serum (6 mg/ml protein) and 10 pl of total fresh milk were applied. Bovine serum albumin (BSA) and immunolactoglobulins (ILG) could also be discriminated. Total fresh milk was as useful as the purified serum milk proteins for the discrimination of ALA and BLG serum milk protein polymorphism by alkaline vertical slab polyacrylamide gel electrophoresis. However, BSA and ILG ran with caseins, which prevented their characterization in this system.

Chemical communication, aggression, and conspecific recognition in the fish Nile tilapia

The chemical modulation of agonistic behavior and conspecific recognition were tested in juveniles of the fish Nile tilapia, Oreochromis niloticus (L.). After a 7-day isolation period, the fish were grouped (four individuals per aquarium) for 7 days. Then fish of alpha and beta ranks (previously matched for similar size) were paired in a neutral territory for analysis of their agonistic interaction. Pairs composed of alpha and beta fish were established with either fish from the same group (familiar) or from two different groups (unfamiliar). The pairs were tested in contiguous compartments, either with water exchange between the compartments or in the absence of water exchange. In each condition the fish were separated by a transparent glass partition. Twelve pairs were tested in each experimental condition. Fish behavior was videotaped and the following variables were analyzed: (a) frequency of and time spent in agonistic patterns, (b) latency to start fighting, and (c) duration of swimming. Water exchange between compartments decreased agonistic interactions. This effect, however, was more pronounced in pairs of fish coming from the same group (in this case, subordinate fish spent less time in confrontations than dominant ones). We conclude that chemical communication decreases aggression in this species by (1) inducing an alarm reaction and (2) increasing conspecific recognition (thus stabilizing the dominance hierarchy). (C) 1997 Elsevier B.V.

Structural and functional characterization of neuwiedase, a nonhemorrhagic fibrin(ogen)olytic metalloprotease from Bothrops neuwiedi snake venom

A fibrino(geno)lytic nonhemorrhagic metalloprotease (neuwiedase) was purified from Bothrops neuwiedi snake venom by a single chromatographic step procedure on a CM-Sepharose column, Neuwiedase represented 4.5% (w/w) of the crude desiccated venom, with an approximate Mr of 20,000 and pI 5.9, As regards the amino acid composition, neuwiedase showed similarities with other metalloproteases, with high proportions of Asx, Glx, Leu, and Ser, Atomic absorption spectroscopy showed that one mole of Zn2+ and one mole of Ca2+ were present per mole olf protein. The cDNA encoding neuwiedase was isolated by RT-PCR from venom gland RNA, using oligonucleotides based on the partially determined amino-acid sequences of this metalloprotease. The fall sequence contained approximately 594 bp, which codified the 198 amino acid residues with an estimated molecular weight of 22,375. Comparison of the nucleotide and amino acid sequences of neuwiedase with those of other snake venom metalloproteases showed a high level of sequential similarity, Neuwiedase has two highly conserved characteristics sequences H(142)E(143)XXH(146)XXG(140)XXH(152) and C164I165M166. The three-dimensional structure of neuwiedase was modeled based on the crystal structure of Crotalus adamanteus Adamalysin II. This model revealed that the zinc binding site region showed a I high structural similarity with other metalloproteases,, the proteolyitc specificity, using the B beta-chain of oxidized insulin as substrate, was shown to be directed to the Ala(14)-Leu(15) and Tyr(16)-Leu(17) peptide bonds which were preferentially hydrolyzed. Neuwiedase is a A alpha,B beta fibrinogenase, Its activity upon the A alpha chain of fibrinogen was detected within 15 min of incubation. The optimal temperature and pH for the degradation of both A alpha and B beta chains were 37 degrees C and 7.4-8.0, respectively. This activity was inhibited by EDTA and 1,10-phenantroline, Neuwiedase also showed proteolytic activity upon fibrin and some components of the extracellular matrix. However, it did not show TAME esterase activity and was not able to inhibit platelet aggregation. (C) 2000 Academic Press.

Kinetic and mechanistic characterization of the Sphingomyelinases D from Loxosceles intermedia spider venom

Envenomation by arachnids of the genus Loxosceles leads to local dermonecrosis and serious systemic toxicity mainly induced by sphingomyelinases D (SMase D). These enzymes catalyze the hydrolysis of sphingomyelin resulting in the formation of ceramide-phosphate and choline as well as the cleavage of lysophosphatidyl choline generating the lipid mediator lysophosphatidic acid. We have, previously, cloned and expressed two functional SMase D isoforms, named P1 and P2, from Loxosceles intertnedia venom and comparative protein sequence analysis revealed that they are highly homologous to SMase I from Loxosceles laeta which folds to form an (alpha/beta)(8) barrel. In order to further characterize these proteins, pH dependence kinetic experiments and chemical modification of the two active SMases D isoforms were performed. We show here that the amino acids involved in catalysis and in the metal ion binding sites are strictly conserved in the SMase D isoforms from L. intermedia. However, the kinetic studies indicate that SMase P1 hydrolyzes sphingomyelin less efficiently than P2, which can be attributed to a substitution at position 203 (Pro-Leu) and local amino acid substitutions in the hydrophobic channel that could probably play a role in the substrate recognition and binding. (c) 2005 Elsevier Ltd. All rights reserved.

Crystal and molecular structures of 4-substituted 3,4-dihydropyrimidin-2(1H)-ones studied by X-ray and AM1 and B3LYP calculations

(1) C13H13N3O5, Mr = 291.26, P (1) over bar, a = 7.4629(9), b = 7.9203(9), c = 12.126(2) angstrom, alpha = 86.804(5), beta = 78.471(7), gamma = 69.401(8)degrees, V = 657.3(2)angstrom(3), Z = 2, R-1 = 0.0454; (2) C11H12N2O4, Mr=236.23, Pbca, a=7.2713(9), b=14.234(1), c=20.848(3)angstrom, V= 2157.8(4) angstrom(3), Z=8, R-1=0.0504; (3) C13H13N2O3Cl, Mr = 280.70, P2/n, a = 17.344(2), b = 9.237(1), c = 18.398(2) angstrom; beta = 92.61(2)degrees, V = 2944.4(6) angstrom(3), Z = 8, R-1 = 0.0714. The conformational features of three 4-substituted-3-4-dihydropyrimidin-2(1H)-ones were investigated by computational and single crystal X-ray crystallographic studies. The geometries were optimized using semiempirical (AM1) and first principle calculations (B3LYP/6-31G**) methods, the rotational barriers for important functional groups were studied. In all structures the pyrimidinone rings are in a more or less distorted boat conformation. The phenyl and the furane rings are almost perpendicular to the best least-squares plane through the dihydropyrimidinone ring.

Development of alpha-SiAlON-SiC ceramic composites by liquid phase sintering

In this work, in situ alpha-SiAlON-SiC ceramic composites were obtained,by, liquid phase sintering, using SiC as reinforcement. Different beta-SiC powder contents (0-20 wt.%), were added to Si3N4-AlN-RE2O3. powder mixtures, and compacted by cold isostatic pressing. The samples were sintered at 1950 degrees C for 1 h, in N-2 atmosphere. Sintered: samples were characterized by relative density, weight loss, X-ray diffraction and scanning electron microscopy. Furthermore, mechanical properties such as hardness and fracture toughness were determined by Vickers indentation method. Lattice parameters of the alpha' phase did not considerably change with increase of SiC content. However, morphology, average grain size and aspect ratio of the alpha' phase were considerably changed with increase of the SiC content. These behavior influences significantly the mechanical properties of this hard ceramic composite. (C) 2006 Elsevier Ltd. All rights reserved.

Host-guest complexation of a nitroheterocyclic compound with cyclodextrins: a spectrofluorimetric and molecular modeling study

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A new ent-kaurane diterpene from stems of Alibertia macrophylla K. Schum. (Rubiaceae)

Phytochemical investigations of the stems of a specimen of Alibertia macrophylla led to the isolation and characterization of the new diterpene ent-kaurane-2β,3α,16α-triol (1), along with triterpenes 2-8, iridoids 9-12, and phenolic acids 13-15. The structure of 1 was established based on spectroscopic studies (1H- and 13C-NMR, IR, and HR-ESI-MS). This is the first report of the isolation of a diterpene from the Alibertia genus in Rubiaceae. © 2007 Verlag Helvetica Chimica Acta AG.

Interclonal Variations in the Molecular Karyotype of Trypanosoma cruzi: Chromosome Rearrangements in a Single Cell-Derived Clone of the G Strain

Trypanosoma cruzi comprises a pool of populations which are genetically diverse in terms of DNA content, growth and infectivity. Inter- and intra-strain karyotype heterogeneities have been reported, suggesting that chromosomal rearrangements occurred during the evolution of this parasite. Clone D11 is a single-cell-derived clone of the T. cruzi G strain selected by the minimal dilution method and by infecting Vero cells with metacyclic trypomastigotes. Here we report that the karyotype of clone D11 differs from that of the G strain in both number and size of chromosomal bands. Large chromosomal rearrangement was observed in the chromosomes carrying the tubulin loci. However, most of the chromosome length polymorphisms were of small amplitude, and the absence of one band in clone D11 in relation to its reference position in the G strain could be correlated to the presence of a novel band migrating above or below this position. Despite the presence of chromosomal polymorphism, large syntenic groups were conserved between the isolates. The appearance of new chromosomal bands in clone D11 could be explained by chromosome fusion followed by a chromosome break or interchromosomal exchange of large DNA segments. Our results also suggest that telomeric regions are involved in this process. The variant represented by clone D11 could have been induced by the stress of the cloning procedure or could, as has been suggested for Leishmania infantum, have emerged from a multiclonal, mosaic parasite population submitted to frequent DNA amplification/deletion events, leading to a 'mosaic' structure with different individuals having differently sized versions of the same chromosomes. If this is the case, the variant represented by clone D11 would be better adapted to survive the stress induced by cloning, which includes intracellular development in the mammalian cell. Karyotype polymorphism could be part of the T. cruzi arsenal for responding to environmental pressure. © 2013 Lima et al.

Chemical characterization and acaricide potential of essential oil from aerial parts of Tagetes patula L. (Asteraceae) against engorged adult females of Rhipicephalus sanguineus (Latreille, 1806)

Rhipicephalus sanguineus, commonly known as the brown dog tick, is one of the most widely distributed species of tick. In dogs, it can cause anemia and provide the transmission of pathogenic microorganisms such as Babesia canis, Ehrlichia canis, Hepatozoon canis, Anaplasma platys, and Mycoplasma haemocanis. To man, it can transmit the intracellular parasites Rickettsia rickettsii and Rickettsia conorii, the causative agents of the Rocky Mountain spotted fever in the Americas and Mediterranean and spotted fever in Europe and North Africa. Its control is performed by applying synthetic formulations composed of pyrethroids; however, continued use of these products results in environmental damage and acquisition of resistance. Alternatively, studies with botanical insecticides have been increasingly recurrent. Therefore, this study aimed to test the efficacy of essential oil of Tagetes patula, a ruderal species widely described in the literature for its insecticidal properties, in engorged females of R. sanguineus by the adults immersion test (AIT) and impregnated paper disk test (IPDT). The essential oil used, through gas chromatography coupled to mass spectrometry, revealed the presence of 55 compounds, being the 4-vinyl guaiacol and gamma terpinene the majority ones. The AIT compared to the IPDT was more efficient in inhibiting oviposition of tick; however, the eggs laid by the females submitted to saturated atmosphere with essential oil, from IPDT, not hatched, interrupted their development cycle. Besides being a pioneer work, the results presented here contributes to new researches, aiming the incorporation of essential oil in an acaricide for use in the environment. © 2013 Springer-Verlag Berlin Heidelberg.

Erythrina mulungu Alkaloids Are Potent Inhibitors of Neuronal Nicotinic Receptor Currents in Mammalian Cells

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Retenção de placenta no proteinograma de vacas Holandesas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Determination of estrogenic mycotoxins in environmental water samples by low-toxicity dispersive liquid-liquid microextraction and liquid chromatography-tandem mass spectrometry

A novel, simple, rapid and eco-friendly method based on dispersive liquid-liquid microextraction using a bromosolvent was developed to determine six estrogenic mycotoxins (zearalenone, zearalanone, alpha-zearalanol, beta-zearalanol, alpha-zearalenol and beta-zearalenol) in water samples by liquid chromatography-electrospray ionization tandem mass spectrometry in the negative mode (LC-ESI-MS/MS). The optimal conditions for this method include the use of 100 mu L bromocyclohexane as an extraction solvent (using a non-dispersion solvent), 10 mL of aqueous sample (adjusted to pH 4), a vortex extraction time of 2 min, centrifugation for 10 min at 3500 rpm and no ionic strength adjustment. The calibration function was linear and was verified by applying the Mandel fitting test with a 95% confidence level. No matrix effect was observed. According to the relative standard deviations (RSDs), the precision was better than 13% for the repeatability and intermediate precision. The average recoveries of the spiked compounds ranged from 81 to 118%. The method limits of detection (LOD) and quantification (LOQ) considering a 125-fold pre-concentration step were 4-20 and 8-40 ng L-1, respectively. Next, the method was applied to the analysis of the environmental aqueous samples, demonstrating the presence of beta-zearalanol and zearalanone in the river water samples. (C) 2015 Elsevier B.V. All rights reserved.