Ildenize Barbosa da Silva Cunha

Ambient mass spectrometry: bringing MS into the "real world".

AbstractMass spectrometry has recently undergone a second contemporary revolution with the introduction of a new group of desorption/ionization (DI) techniques known collectively as ambient mass spectrometry. Performed in an open atmosphere directly on samples in their natural environments or matrices, or by using auxiliary surfaces, ambient mass spectrometry (MS) has greatly simplified and increased the speed of MS analysis. Since its debut in 2004 there has been explosive growth in the applications and variants of ambient MS, and a very comprehensive set of techniques based on different desorption and ionization mechanisms is now available. Most types of molecules with a large range of masses and polarities can be ionized with great ease and simplicity with the outstanding combination of the speed, selectivity, and sensitivity of MS detection. This review describes and compares the basis of ionization and the concepts of the most promising ambient MS techniques known to date and illustrates, via typical analytical and bioanalytical applications, how ambient MS is helping to bring MS analysis deeper than ever into the “real world” open atmosphere environment—to wherever MS is needed. FigureSchematic of EASI

Phenolic Antioxidants Identified by ESI-MS from Yerba Maté (Ilex paraguariensis) and Green Tea (Camelia sinensis) Extracts

Aqueous extracts of green yerba maté (Ilex paraguariensis) and green tea (Camellia sinensis) are good sources of phenolic antioxidants, as already described in the literature. The subject of this study were organic extracts from yerba maté, both green and roasted, and from green tea. Their phenolic profiles were characterized by direct infusion electrospray insertion mass spectrometry (ESI-MS) and their free radical scavenging activity was determined by the DPPH assay. Organic extracts containing phenolic antioxidants might be used as natural antioxidants by the food industry, replacing the synthetic phenolic additives used nowadays. Ethanolic and aqueous extracts from green yerba maté, roasted yerba maté and green tea showed excellent DPPH scavenging activity (>89%). The ether extracts from green and roasted yerba maté displayed a weak scavenging activity, different from the behavior observed for the green tea ether extract. The main phenolic compounds identified in green yerba maté water and ethanolic extracts were: caffeic acid, quinic acid, caffeoyl glucose, caffeoylquinic acid, feruloylquinic acid, dicaffeoylquinic acid and rutin. After the roasting process two new compounds were formed: caffeoylshikimic acid and dicaffeoylshikimic acid. The ethanolic extracts from yerba maté, both roasted and green, with lower content of phenolic compounds (3.80 and 2.83 mg/mL) presented high antioxidant activity and even at very low phenolic concentrations, ether extract from GT (0.07 mg/mL) inhibited DPPH over 90%.

Electrospray ionization mass spectrometry fingerprinting of propolis

Crude ethanolic extracts of propolis, a natural resin, have been directly analysed using electrospray ionization mass (ESI-MS) and tandem mass spectrometry (ESI-MS/MS) in the negative ion mode. European, North American and African samples have been analyzed, but emphasis has been given to Brazilian propolis which displays diverse and region-dependent chemical composition. ESI-MS provides characteristic fingerprint mass spectra, with propolis samples being divided into well-defined groups directly related to their geographical origins. Chemometric multivariate analysis statistically demonstrates the reliability of the ESI-MS fingerprinting method for propolis. On-line ESI-MS/MS tandem mass spectrometry of characteristic [M - H](-) ion markers provides an additional dimension of fingerprinting selectivity, while structurally characterizing the ESI-MS marker components of propolis. By comparison with standards, eight such markers have been identified: para-coumaric acid, 3-methoxy-4-hydroxycinnamaldehyde, 2,2-dimethyl-6-carboxyethenyl-2H-1-benzopyran, 3-prenyl-4-hydroxycinnamic acid, chrysin, pinocembrin, 3,5-diprenyl-4-hydroxycinnamic acid and dicaffeoylquinic acid. The negative mode ESI-MS fingerprinting method is capable of discerning distinct composition patterns to typify, to screen the sample origin and to reveal characteristic details of the more polar and acidic chemical components of propolis samples from different regions of the world.

Instantaneous characterization of vegetable oils via TAG and FFA profiles by easy ambient sonic-spray ionization mass spectrometry

A fast and reliable method is presented for the analysis of vegetable oils. Easy ambient sonic-spray ionization mass spectrometry (EASI-MS) is shown to efficiently desorb and ionize the main oil constituents from an inert surface under ambient conditions and to provide comprehensive triacylglyceride (TAG) and free fatty acid (FFA) profiles detected mainly as either [TAG + Na](+) or [FFA-H](-) ions. EASI(+/-)-MS analysis is simple, easily implemented, requires just a tiny droplet of the oil and is performed without any pre-separation or chemical manipulation. It also causes no fragmentation of TAG ions hence diacylglyceride (DAG) and monoacylglyceride (MAG) profiles and contents can also be measured. The EASI(+/-)-MS profiles of TAG and FFA permit authentication and quality control and can be used, for instance, to access levels of adulteration, acidity, oxidation or hydrolysis of vegetable oils in general.

Analytical methods applied to diverse types of Brazilian propolis

Propolis is a bee product, composed mainly of plant resins and beeswax, therefore its chemical composition varies due to the geographic and plant origins of these resins, as well as the species of bee. Brazil is an important supplier of propolis on the world market and, although green colored propolis from the southeast is the most known and studied, several other types of propolis from Apis mellifera and native stingless bees (also called cerumen) can be found. Propolis is usually consumed as an extract, so the type of solvent and extractive procedures employed further affect its composition. Methods used for the extraction; analysis the percentage of resins, wax and insoluble material in crude propolis; determination of phenolic, flavonoid, amino acid and heavy metal contents are reviewed herein. Different chromatographic methods applied to the separation, identification and quantification of Brazilian propolis components and their relative strengths are discussed; as well as direct insertion mass spectrometry fingerprinting.Propolis has been used as a popular remedy for several centuries for a wide array of ailments. Its antimicrobial properties, present in propolis from different origins, have been extensively studied. But, more recently, anti-parasitic, anti-viral/immune stimulating, healing, anti-tumor, anti-inflammatory, antioxidant and analgesic activities of diverse types of Brazilian propolis have been evaluated. The most common methods employed and overviews of their relative results are presented.

Fatty acid composition and palynological analysis of bee (Apis) pollen loads in the states of São Paulo and Minas Gerais, Brazil

SUMMARY The fatty-acid composition and botanical origin of 14 honey bee (Apis mellifera) pollen load samples acquired in shops and apiaries in Minas Gerais and São Paulo states, Brazil, were determined. The fatty acids presented a variable composition among these samples. All samples contained oleic, linoleic and arachidic acid. Only one sample did not contain palmitic acid. The unsaturated fatty-acid level varied from 18.6% to 55.9% of the total fatty-acid composition, suggesting that pollen is a good source of unsaturated fatty acids to the diet. Several pollen types were identified. Eucalyptus (Myrtaceae) and Eupatorium (Asteraceae) pollen types were the most common among those sampled. These data might help the regulatory agencies establish quality parameters for pollen produced in Brazil. There are no additional data available on Brazilian pollen fatty acid composition.

Standard methods for Apis mellifera propolis research

Propolis is one of the most fascinating honey bee (Apis mellifera L.) products. It is a plant derived product that bees produce from resins that they collect from different plant organs and with which they mix beeswax. Propolis is a building material and a protective agent in the bee hive. It also plays an important role in honey bee social immunity, and is widely used by humans as an ingredient of nutraceuticals, over-the-counter preparations and cosmetics. Its chemical composition varies by geographic location, climatic zone and local flora. The understanding of the chemical diversity of propolis is very important in propolis research. In this manuscript, we give an overview of the available methods for studying propolis in different aspects: propolis in the bee colony; chemical composition and plant sources of propolis; biological activity of propolis with respect to bees and humans; and approaches for standardization and quality control for the purposes of industrial application.

Electrospray ionization mass spectrometry fingerprinting of propolis of native Brazilian stingless bees

Stingless bees are found in many tropical and subtropical regions of the word. The knowledge of the composition of their propolis as well as the plants that are visited as sources of resins is therefore of prime importance. Here the negative ion mode electrospray ionization mass spectrometry [ESI(-)-MS] fingerprints of propolis from various species of native stingless bees from different regions in Brazil are compared to determine their composition patterns. The correlation among the propolis samples was investigated via chemometric analysis.ZusammenfassungStachellose Bienen kommen in vielen tropischen und subtropischen Regionen der Welt vor und sind in diesen Regionen wichtige Bestäuber. Nichtsdestotrotz ist die Haltungstechnologie für die meisten Arten Stachelloser Bienen noch auf einem relativ niedrigen Niveau. Obwohl für Brasilien bereits verschiedene Studien zur Nischenüberlappung von einheimischen Bienen mit den eingeführten Honigbienen vorliegen, gibt es nur wenig Informationen zu Pflanzen, die von Stachellosen Bienen als Harzquelle für die Herstellung von Propolis genutzt werden. Propolisproben, die von Imkern in verschiedenen Regionen Brasiliens gewonnen wurden (zusammengestellt in Tab. 1), wurden eingefroren und für die Extraktion zermahlen. Die mazerierten Proben wurden auf einem Schüttler während sieben Tagen in Alkohol extrahiert und anschliessend im negativen Ionenmodus per Elektrospray-Ionisations-Massenspektrometrie [ESI(-)-MS] in einem Q-TOF-Massenspektrometer (Micromass) analysiert. Mittels einer chemometrischen Hauptkomponentenanalyse (PCA) wurden statistisch signifikante Korrelationen in diesen Fingerabdrucksanalysen der Propolisproben aufgedeckt. Abbildung 1 zeigt die PCA-Ergebnisse der ESI(-)-MS Fingerabdrücke von Propolisproben Stachelloser Bienen und von Honigbienen. Die Proben teilen sich anhand ihrer charakteristischen Ionen klar in drei Gruppen auf (Abb. 1 A, B). Abbildung 2 zeigt ESI(-)-MS-Spektren typischer Proben aus jeder dieser Gruppen. Gruppe 1 besteht aus neun Propolisproben, für die die Ionen m/z 371, 373, 401, 453, 455, 469 und 471 für die Gruppierung verantwortlich sind. Diese Ionen sind charakteristisch für Tetragonisca angustula Propolis, die diese Bienen in ganz Brasilien überwiegend von Schinus terebenthifolius sammeln. Gruppe 2 besteht ebenfalls aus neun Propolisproben, mit den Gruppierungsionen m/z 301, 315, 317, 319, 333, and 361. Diese sind für die braune A. mellifera Propolis charakteristisch, die vor allem aus Südbrasilien stammt und in der die Bienen Harze der Araucaria Tanne verarbeiten. Zwei Propolisproben (P. droryana aus São Paulo und P. remota aus Paraná) lagen zwischen diesen beiden Gruppen (Abb. 1A), was darauf hinweist, dass diese Bienen sowohl S. terebenthifolius als auch Araucaria Harze sammelten. Gruppe 3 besteht aus sechs Propolisproben, für die das Hauption (m/z 271) für die Gruppierung verantwortlich zeigt. Dieses ist charakteristisch für rote Robinienpropolis von A. mellifera aus dem Nordosten Brasiliens. Die meisten Fingerabdrücke von Propolisproben der einheimischen Stachellosen Bienen zeigten die für S. terebenthifolius charakteristischen Ionen. Diese in ganz Brasilien vorkommende Pflanze enthält medizinisch wirksame Substanzen und wird häufig von Stachellosen Bienen besucht. Unsere Ergebnisse zeigen, dass S. terebenthifolius eine wichtige Quelle für die Propolisgewinnung darstellt, dass Stachellose Bienen aber auch andere Pflanzen, insbesondere Aurakarien nutzen können.

Automated gravimetric management of solutions. Part 2. Automated gravimetric approach to direct potentiometry and kappa number determination

The high-performance microcomputer controlled gravimetric burette described in Part 1 has been employed to automate some routine analytical procedures. A direct potentiometric determination of fluoride ions in drinking water was developed to include an automatic calibration step, matrix adjustment and sample determination. Also the complex and cumbersome titrimetric procedure for determination of the kappa number (lignin content) in paper pulp, has been automated by using the gravimetric unit and biamperometry. In this last instance, the automatic standardization of the solutions employed in the determination and the complete automation of the recommended kappa number determination procedure, allows a significant reduction in the amount of reagent consumed. The gravimetric approach to these procedures reveals that the same performance is achieved in terms of precision and accuracy when compared with classic volumetry while the cost associated with the automation decreases owing to the use of the same unit to attain automatic management of up to three different solutions.

Comparative study of the effect of green and roasted water extracts of mate (Ilex paraguariensis) on glucosyltransferase activity of Streptococcus mutans

Glucosyltransferase (GTF) plays an important role in the development of dental caries. This study was carried out to compare the efficiency of green mate (GM) and roasted mate (RM) water extracts, drinks rich in polyphenolic compounds consumed in the subtropical region of South America, on the extracellular GTF activity from Streptococcus mutans. The RM extract exhibited a greater inhibitory effect (IC50 of 10 mg/mL) despite presenting lower polyphenolic content. The kinetic analysis showed that there were significant differences (P < 0.05) between the extracts with respect to the values for Km and Ki, whereas the values for Vmax were the same, implying the competitive nature of GTF inhibition. GTF activity was also measured using selected polyphenols as inhibitors, and the most effective inhibitors were rutin and caffeoylshikimic acid. The characterization of the extracts by ESI-MS and UPLC-MS showed that the compounds formed during roasting, possibly shikimic acid derivatives and other unindentified compounds formed by the Maillard reaction, appeared to contribute to the inhibition of GTF activity.