Comparative analysis of sesquiterpene lactones from <Emphasis Type="Italic">Mikania cordifolia</Emphasis> collected from three different locations

The sesquiterpene lactone composition of extracts of Mikania cordifolia collected from Ribeirao Preto-SP (Brazil), Sao Carlos-SP (Brazil), and Campos de Jordao-SP (Brazil) were comparatively analyzed by HPLC. The results indicate that all specimens have the melampolide type sesquiterpene lactones analyzed and this kind of structure can be used as taxonomic marker for M. cordifolia. Published in Khimiya Prirodnykh Soedinenii, No. 2, pp. 117–118, March–April, 2007.     

A journey through the pre-Budapest-2013 k 0 Users Workshops

A short survey is given of the five meetings preceding the 6th International k ₀ Users Workshop that was held from 22 to 27 September in Budapest/Hungary. These predecessors were the Workshops in: Gent/Belgium (1992), Ljubljana/Slovenia (1996), Bruges/Belgium (2001), Funchal-Madeira/Portugal (2005) and Belo Horizonte/Brazil (2009).     

A novel, sensitive and specific real-time PCR for the detection of traces of allergenic Brazil nut (Bertholletia excelsa) in processed foods

Food-allergic individuals have to strictly avoid the offending food because no causative immunotherapies are available. Thus, reliable labelling of allergenic ingredients or precautionary labelling of cross-contacts with potential allergens is of major importance. Verification of compliance with labelling requirements and identification of cross-contacts demand test methods that enable the specific and sensitive detection of the analyte. Brazil nut (Bertholletia excelsa) is such a food commodity with allergenic potential. We describe the development of a novel qualitative real-time polymerase chain reaction (PCR) specific for Brazil nut DNA and its comparison with a qualitative commercially available lateral flow device (LFD) that detects Brazil nut protein. Specificity was investigated with 58 foods, and no false-positive reactions were observed in real-time PCR. The sensitivity was investigated with spiked chocolate and incurred dough samples as well as cookies baked thereof. The simultaneous spiking of matrices with identical amounts of Brazil nut and peanut between 5 and 100,000 mg/kg allowed the verification of the spike quality with two peanut-specific enzyme-linked immunosorbent assay. The real-time PCR detected Brazil nut in all three matrices down to the lowest investigated spike level of 5 mg/kg. The real-time PCR results from the analysis of 15 retail samples were confirmed by LFD results and were in concordance with the labelling of products. The real-time PCR showed unparalleled specificity, and primary data indicated potentially quantitative features in spiked and retail samples. Because of entirely reproducible chemistry of this real-time PCR, this is the first generally available Brazil nut-specific detection method with an appropriate sensitivity to help avoid severe allergic reactions for Brazil nut-allergic individuals.     

Simulation of aerated lagoon using artificial neural networks and multivariate regression techniques

The aim of this study was to develop an empirical model that provides accurate predictions of the biochemical oxygen demand of the output stream from the aerated lagoon at International Paper of Brazil, one of the major pulp and paper plants in Brazil. Predictive models were calculated from functional link neural networks (FLNNs), multiple linear regression, principal components regression, and partial least-squares regression (PLSR). Improvement in FLNN modeling capability was observed when the data were preprocessed using the PLSR technique. PLSR also proved to be a powerful linear regression technique for this problem, which presents operational data limitations.     

Chemical composition and antimicrobial activities of the essential oils from Ocimum selloi and Hesperozygis myrtoides

Ocimum selloi, a traditional medicinal plant from Brazil, is sold in open-air markets at Rio de Janeiro State. Hesperozygis myrtoides is a very aromatic small bush found in the State of Minas Gerais, Brazil, growing at an altitude of 1800m. The chemical composition of both essential oils was analyzed as well as their antimicrobial activity against fungi and bacteria. For all specimens of Ocimum selloi obtained at open-air markets, methylchavicol was major compound found (93.6% to 97.6%) in their essential oils. The major compounds identified in the oil of H. myrtoides were pulegone (44.4%), isomenthone (32.7%), and limonene (3.5%). Both oils displayed antimicrobial activity against all tested microorganisms but Candida albicans was the most susceptible one. Combinations of the two oils in different proportions were tested to verify their antimicrobial effect against C. albicans, which, however, was not modified in any of the concentrations tested. The minimum inhibitory concentration (MIC) was determined to confirm the antimicrobial activity against C. albicans as well as other clinical isolates (C. glabrata, C. krusei, C. parapsilosis and C. tropicalis).     

A new cyclopeptide alkaloid from the bark of waltheria douradinha

Waltherine-C (5), a novel 14-membered cyclopeptide alkaloid has been isolated, together with four known cyclopeptide alkaloids, waltherine-A (1) and -B (2), scutianine-B (3) and adouetine-Y' (4), from the bark of Waltheria douradinha (Sterculiaceae) from Rio Grande do Sul, Brazil. The structure and NMR assignments of this new alkaloid were determined by 1D and 2D NMR techniques. The stereochemistry of the ring amino acid residue and the N,N-dimethyl amino acid side-chain has been assigned by gas chromatography employing modified cyclodextrins as chiral stationary phases.     

Isolation and structural determination of xerophytolic acid A, a 3-geranyl-4-hydroxybenzoate derivative from Xerophyta plicata

A novel compound of a rare class of secondary metabolites, 3-geranyl-4-hydroxybenzoic acid derivative, methyl xerophytolate A (2), was isolated from the crude extract of Xerophyta plicata (Velloziaceae) collected in Rio de Janeiro, Brazil. The structure of 2 was elucidated using spectroscopic methods.     

The lead assessor role in the ISO/IEC 17025:2005 accreditation of Brazilian calibration and testing laboratories by the General Coordination of Accreditation (Cgcre)

This work describes the human resources organization of the General Coordination for Accreditation (Cgcre) in Brazil, in which lead and technical assessors, both internal and external to the National Institute of Metrology, Quality and Technology (Inmetro), assess the competence of calibration and testing laboratories to the ISO/IEC 17025:2005 standard. The “Lead Assessor Project” is presented, which consists of an increase in the responsibilities of lead assessors, in such a way that the Division of Laboratories Accreditation (Dicla/Cgcre) can cope with the increasing demand for ISO/IEC 17025:2005 accreditation of Brazilian calibration and testing laboratories.     

Application of liquid chromatography/electrospray ionization tandem mass spectrometry to the analysis of polyphenolic compounds from an infusion of Byrsonima crassa Niedenzu

A fast and reliable method, based on high-performance liquid chromatography coupled to electrospray ionization ion trap tandem mass spectrometry (HPLC/ESI-ITMS), was developed to investigate the infusion prepared from the leaves of Byrsonima crassa Niedenzu (Malpighiaceae), a native plant used in Brazil against gastric disorders. The use of on-line reverse-phase HPLC/ESI-ITMS allowed separation of three major classes of compounds and identification of over 20 very polar compounds characterized as galloylquinic acids, proanthocyanidins, and flavonoid glycosides, as well as the dimeric flavonoid amentoflavone and minor amounts of galloyl hexose and galloyl saccharose. This approach provided data that will allow establishment of a method for a future standardization of the infusion.     

Chemical composition and antioxidant, antimicrobial, and larvicidal activities of the essential oils of Annona salzmannii and A. pickelii (Annonaceae)

The essential oils from the leaves of Annona salzmannii and A. pickelii (Annonaceae) growing in Sergipe, northeastern region of Brazil, were obtained by hydrodistillation using a Clevenger-type apparatus, and analyzed by GC/MS and GC/FID. Thirty-four compounds were identified in the essential oil of A. salzmannii and twenty-seven in that of A. pickelii; sesquiterpenes predominated in both essential oils. Bicyclogermacrene (20.3%), (E)-caryophyllene (19.9%), delta-cadinene (15.3%), alpha-copaene (10.0%), and allo-aromadendrene (5.7%) were the main components of A. salzmannii, and bicyclogermacrene (45.4%), (E)-caryophyllene (14.6%), and alpha-copaene (10.6%) of A. pickelii. The essential oils showed significant antioxidant capacity in the ORAC(FL) and DPPH assays. The antimicrobial activity of these essential oils was also evaluated against bacteria and fungi, as well as the larvicidal activity against Aedes aegypti larvae.     

Thermal decomposition of some diuretic agents

Thermogravimetry-derivativc thermogravimetry and differential scanning calorimetry were used to study the thermal behaviour of furosemide, hydrochlorothiazide, spironolactone, and amiloride hydrochloride. The results revealed the extents of their thermal stability and also permitted interpretations concerning their thermal decompositions.The authors thank FAPESP (Proc. 90/2932-4) and CNPq for financial support, and Hoechst of Brazil, Prodome Química e Farmaceutica Ltda, Campinas, Brazil, and Biolab. Industrias Farmaceuticas, Brazil, for supplying the diuretic agents used in this study.     

Elemental analysis of biological tissues of animal models in muscular dystrophies investigation

Element concentrations in biological tissues of Dmd^mdx/J and C57BL/6 J mice strains were determined using the neutron activation analysis technique. Samples of whole blood, bones and organs (heart and muscle) of these strains were irradiated in the IEA–R1 nuclear reactor at IPEN-CNEN/SP (Brazil). To perform this investigation biological samples of two-month-old adult females (n = 10) and males (n = 9) for Dmd^mdx/J (dystrophic mice), and males (n = 12) for C57BL/6 J (control group), originally obtained from the Jackson Laboratory (Maine, USA) and further inbred at IPEN–CNEN/SP (São Paulo, Brazil), were used. A significant change was observed in the analysis of the heart of dystrophic mice suggesting that this dysfunction affects severely the heart muscle. These data may, in the future, contribute to the healthcare area, in veterinary medicine and in the pharmaceutical industry allowing the evaluation of the best procedures in diagnosis, treatment and investigations of neuromuscular diseases (muscular dystrophy) of patients through the use of animal models.     

Thermal Analysis in Examination of Reduction of Blast Furnace Pellets

This paper presents applications of thermal analysis to observe the course of reduction of acidic pellets, metallurgical substances whose reducibility and strength are basic parameters of use in blast furnace processes. Both parameters depend on the mineral composition of the samples. The investigations included determination of the chemical and phase compositions of the initial samples and reduction products. Research was conducted on acidic pellets from Połtawa (Poland), applied in the T. Sendzimir Steelworks (Poland), in comparison with pellets from Brazil, Canada and Lebedyn (Russia). This revised version was published online in August 2006 with corrections to the Cover Date.     

Antioxidant capacity and phenolic content of four Myrtaceae plants of the south of Brazil

Antioxidant compounds can be useful to prevent several degenerative diseases or as preservative in food and toiletries. Species of the Myrtaceae family are able to accumulate phenolic substances and those are closely related to the antioxidant activity due to their capacity to scavenge free radicals, protect against lipid peroxidation and quench reactive oxygen species. These facts prompted us to investigate the antioxidant capacity of the ethanolic extracts of the leaves of four Myrtaceae plants collected of the south of Brazil: Eugenia chlorophylla O. Berg., Eugenia pyriformis Cambess, Myrcia laruotteana Cambess and Myrcia obtecta (Berg) Kiacrsk. The antioxidant potential was performed using the DPPH (a single electron transfer reaction based assay) and ORAC (Oxygen Radical Absorbance Capacity, a hydrogen atom transfer reaction based assay) assays. Moreover, the total soluble phenolic content was also measured using the Folin-Ciocalteu reagent. A preliminary evaluation of the ethanolic extracts of these Myrtaceae plants revealed high levels of phenolic compounds (343.7-429.3 mg GAE) as well as high antioxidant activity according to both methods (1338 a 3785 micromol of TE/g of extract in ORAC and SC50 in the range of 1.70 and 33.7 microg/mL in the DPPH). The highest antioxidant activity obtained by DPPH assay was exhibited by ethanol extract of the leaves of E. pyriformis (1.70 microg/mL), followed by extracts of M. laruotteana (3.38 microg/mL) and M. obtecta (6.66 microg/mL). In comparison with controls, in the DPPH assay, the extract of E. pyriformis was more active than trolox (SC50 = 2.55 microg/mL), while the extracts of M. laruotteana and M. obtecta were more actives than quercetin (SC50 = 7.80 microg/mL). In the ORAC assay, all species also show good antioxidant capacity (>1000 micromol of TE/g). Initial HPLC-UV/DAD and ESI-MS confirmed the presence of phenolic acids constituents in the ethanol extracts. The results indicate the presence of compounds possessing promising antioxidant/free-radical scavenging activity in the analyzed extracts of Myrcia and Eugenia plants of the south of Brazil.     

Thermal behavior and evolution of the mineral phases of Brazilian red mud

This article studied the thermal behavior and the evolution of the crystalline phases with temperature of the red mud (bauxite tailing) from an aluminum industry at Maranhão, North-Northwestern Brazil. The experiments were carried out by Field Emission Scanning Electron Microscopy (FE-SEM), Simultaneous Thermal Analysis (TG–DSC), Optical Dilatometry up to 1623 K, and X-ray diffraction (XRD) of previously heated samples between 523 and 1523 K. The crystalline phases and the amorphous contents were quantified on raw and heated samples (at 1523 K) according to the Rietveld Quantitative Analysis (RQA) method. The data obtained showed that the raw red mud is composed by a mixture of seven different phases (hematite, goethite, sodalite, anatase, gibbsite, calcite, and amorphous). Finally in the interval of 1023–1523 K the following crystalline phases: hematite, nepheline, sodalite, anatase, perovskite, and pseudobrookite have been observed.     

Seasonal variation in the chemical composition and antimicrobial activity of volatile oils of three species of Leptospermum (Myrtaceae) grown in Brazil

This study investigates the seasonal variation of three species of Leptospermum (Myrtaceae) grown in Brazil. The chemical composition of the volatile oils of L. flavescens and L. petersonii did not show any significant seasonal variation in the major components, while for Leptospermum madidum subsp. sativum the levels of major constituents of the volatile oils varied with the harvest season. Major fluctuations in the composition of L. madidum subsp. sativum oil included α-pinene (0-15.2%), β-pinene (0.3-18.5%), α-humulene (0.8-30%), 1,8-cineole (0.4-7.1%) and E-caryophyllene (0.4-11.9%). Levels of β-pinene (0.3-5.6%), terpinen-4-ol (4.7-7.2%) and nerolidol (55.1-67.6%) fluctuated seasonally in the L. flavescens oil. In L. petersonii, changes were noted for geranial (29.8-32.8%), citronellal (26.5-33.9%) and neral (22.7-23.5%). The activity of the volatile oils against the tested bacteria differed, depending on season the oils were obtained. In general, the volatile oils were more active against Gram-positive bacteria.     

Design of Nanostructured Lipid Carriers Containing Cymbopogon martinii (Palmarosa) Essential Oil against Aspergillus nomius

Palmarosa essential oil (PEO) is an alternative to synthetic fungicides to control the contamination by food-deteriorating fungi, such as Aspergillus nomius. Nonetheless, the low long-term stability and volatility hamper its utilization. Thus, this study aimed to develop nanostructured lipid carriers (NLCs) containing PEO to improve its stability and consequently prolong the activity against A. nomius. A mixture design was applied to find the best preparation conditions for antifungal activity. The characterization analyses included size measurements, zeta potential (ζ-potential), entrapment efficiency (EE), and antifungal activity (by inhibition of mycelial growth (IMG) and/or in situ test (pre-contaminated Brazil nuts) tests). The nanocarriers presented particle sizes smaller than 300 nm, homogeneous size distribution, ζ-potential of −25.19 to −41.81 mV, and EE between 73.6 and 100%. The formulations F5 and F10 showed the highest IMG value (98.75%). Based on the regression model, three optimized formulations (OFs) were tested for antifungal activity (IMG and in situ test), which showed 100% of inhibition and prevented the deterioration of Brazil nuts by A. nomius. The preliminary stability test showed the maintenance of antifungal activity and physicochemical characteristics for 90 days. These results suggest a promising system as a biofungicide against A. nomius.     

Research on analytical chemistry in Brazil: an overview

An overview is presented of the beginnings, evolution and current status of research on analytical chemistry in Brazil. Among the various fields of chemistry two decades ago, Analytical Chemistry was considered one of the least developed in Brazil. In the last 15 years, however, research and development in this field have expanded considerably and today it is one of the most highly developed fields of Chemistry in Brazil. This paper offers a general overview of this evolution and some suggestions for possible routes for the future of analytical chemistry in Brazil.     

Thermal analysis as a tool in the study of GMM in Angra Dos Reis region,Rio de Janeiro,Brazil

Angra dos Reis/Itaguai region of the state of Rio de Janeiro, Brazil, is a very problematic area due to the instability of slope and landslides, due to geological and geomorphological conditions and to the significant and continuous human occupation over favorable areas is prone to the triggering of landslides. The samples were analyzed by thermogravimetry (TG), derivative thermogravimetry (DTG) and differential thermal analysis (DTA). This paper analyzes and characterizes the clay minerals and presence of water, gravitational mass movements’ sites and compares it with sites where gravitational mass movements do not occur. Indeed, this analysis also attempts to verify the presence of minerals.     

Alkaloids from stems of Esenbeckia leiocarpa Engl. (Rutaceae) as potential treatment for Alzheimer disease

Esenbeckia leiocarpa Engl. (Rutaceae), popularly known as guarant?, goiabeira, is a native tree from Brazil. Bioactivity-guided fractionation of the ethanol stems extract afforded the isolation of six alkaloids: leiokinine A, leptomerine, kokusaginine, skimmianine, maculine and flindersiamine. All isolated compounds were tested for acetyl cholinesterase inhibition, in vitro and displayed anticholinesterasic activity. The alkaloid leptomerine showed the highest activity (IC?? = 2.5 mM), similar to that of the reference compound galanthamine (IC?? = 1.7 mM). The results showed for the first time the presence of alkaloids leptomerine and skimmianine in E. leiocarpa (Engl.) with potent anticholinesterasic activity.