Eduardo Morgado Schmidt

Phytochemical markers of different types of red propolis.

Propolis is a resin that bees collect from different plant sources and use in the defense of the bee community. The intricate composition of propolis varies depending on plant sources from different geographic regions and many types have been reported. Red coloured propolis found in several states in Brazil and in other countries has known antimicrobial and antioxidant activity. Different analytical methods have been applied to studies regarding the chemical composition and plant origins of red propolis. In this study samples of red propolis from different regions have been characterised using direct infusion electrospray ionisation mass spectrometry (ESI(-)-MS) fingerprinting. Data from the fingerprints was extracted and analysed by multivariate analysis to group the samples according to their composition and marker compounds. Despite similar colour, the red coloured propolis samples were divided into three groups due to contrasting chemical composition, confirming the need to properly characterise the chemical composition of propolis.

Composição química e atividade biológica de extrato oleoso de própolis: uma alternativa ao extrato etanólico

Propolis is mostly used as hydroalcoholic extract. Recently there has been a growing number of patents dealing with new solvents for preparing propolis extracts. This study aimed to prepare edible oil propolis extracts and compare their chemical composition and biological activity with ethanolic propolis extracts. ESI-MS and spectrophotometric methods were used for qualitative and quantitative analyses, respectively. Antibacterial activity was evaluated by diffusion in agar. Cytotoxicity was tested by MTT assay using tumor cell lines. The oil is able to extract bioactive compounds from propolis. Further studies are needed to improve extraction efficiency and to characterize the active components.

Charge-tagged acetate ligands as mass spectrometry probes for metal complexes investigations: applications in Suzuki and Heck phosphine-free reactions.

An acetate anion bearing an imidazolium cation as its charge tag was reacted with M(OAc)(2) complexes (where M = Ni, Cu, and Pd; in situ reaction) to form members of a new class of charge-tagged metal complexes. The formation of these unprecedented precatalysts with potential for cross-coupling reactions was confirmed by electrospray ionization (and tandem) mass spectrometry. The catalytic performance of the palladium complex was tested in Heck and Suzuki cross-coupling reactions, often with superior activity and yields as compared with Pd(OAc)(2).

Petroleomics by ion mobility mass spectrometry: resolution and characterization of contaminants and additives in crude oils and petrofuels

Ion mobility-mass spectrometry (IM-MS), performed with exceptional resolution and sensitivity in a new uniform-field drift tube ion mobility quadrupole time-of-flight (IM-QTOF) instrument, is shown to provide a useful tool for resolving and characterizing crude oils and their contaminants, as well as petrofuels and their additives. Whereas direct analysis of a crude oil sample contaminated with demulsifiers by the classical ESI(±)-FTICR-MS petroleomic approach was unsatisfactory since it responds only with abundance and m/z, and ionization is impaired due to suppression of polar compounds of crude oil by additives likely used in petroleum industry, IM-MS enables mobility separation of ions, particularly of double bond equivalent (DBE) series for a giving CnX class providing separated spectra which are typical obtained either for the crude oil or the contaminants, even suffering of ion suppression or low ionization efficiency. The combination of improved IM resolution and high mass resolving power (40,000@400) of the QTOF instrument provides useful information on class (N, NO, NS, etc.), carbon number (Cn), and unsaturation (DBE) levels for crude oils, allowing one to infer geochemical properties from DBE trends that can be compared with IM-MS data. As demonstrated by results of gasoline samples with additives, the IM-MS system also allows efficient separation and characterization of additives and contaminants in petrofuels.

A Comparison between Characterization and Biological Properties of Brazilian Fresh and Aged Propolis

Objective. As propolis is a highly valued bee product, we aimed to verify the quality of aged propolis, investigating their phenolic and flavonoid composition, levels of toxic metals, radical scavenging and antimicrobial activities. Material and Methods. Samples of fresh and aged propolis of six different beekeepers, from the same geographical location, were investigated in terms of their phenolic and flavonoid composition and levels of Pb, Cd, and Cr, as well as radical scavenging and antimicrobial activities. Results. The two groups of propolis had similar qualitative composition by HPLC-PDA and ESI(-)-MS. Fresh propolis and aged propolis show no differences when average values of extraction yield, flavonoids, EC50, or MIC were compared and both types of propolis showed good antimicrobial activity at low concentrations. Only levels of phenolic compounds were higher in fresh propolis. Conclusion. The propolis samples considered in this study, aged or fresh, had similar qualitative composition, although they were collected in different periods. Samples only differed in their levels of total phenolic content. Moreover, aged propolis conserves significant radical scavenging and antimicrobial properties. We suggest that aged propolis should not be discarded but explored for alternative applications.

Quantitation of organic acids in wine and grapes by direct infusion electrospray ionization mass spectrometry

Several organic acids such as malic, tartaric and citric acids are key grape and wine constituents. They greatly contribute to the organoleptic properties of grapes and wines and are responsible for their acidity, a crucial wine property that is known to considerably vary as a function of grape variety, environmental conditions and viticulture, as well as during wine maturation. A rapid and simple method, requiring minimum sample pre-treatment and no chromatographic separation, based on direct infusion electrospray ionization mass spectrometry (ESI-MS) was developed and validated to quantitate organic acids in wines and grapes. This method was also demonstrated to be able to monitor a common wine adulteration procedure, that is, addition of citric acid for pH adjustment. ESI-MS data when treated via principal component analysis (PCA) was also found to group wine samples based on their profiles and concentrations of organic acids.

Characterization of anti-theft devices directly from the surface of banknotes via easy ambient sonic spray ionization mass spectrometry

Using Brazilian banknotes as a test case, forensic examination and identification of Rhodamine B dye anti-theft device (ATD) staining on banknotes were performed. Easy ambient sonic spray ionization mass spectrometry (EASI-MS) was used since it allows fast and simple analysis with no sample preparation providing molecular screening of the surface with direct desorption and ionization of the security dye. For a more accurate molecular characterization of the ATD dye, Q Exactive Orbitrap™ Fourier transform (tandem) mass spectrometry using eletrospray ionization (ESI-HRMS/MS) was also applied.

Effect of extraction solvent on antiradical activity of the obtained propolis extracts

Summary Total phenolic, flavonoid and mineral contents and antiradical activity are usually used as a measure of propolis extract quality. The purpose of this study was to compare the quality of propolis extracts obtained with different solvents such as water, ethanolic solutions (30, 70, 95%, v/v in water) and edible vegetable oils (canola and soybean). LC-MS was used to identify constituents of the extracts. Antiradical activity was assayed using chemiluminescence from the luminol/hemin/H2O2/CTAB system and the DPPH test. Both antiradical assays were strongly correlated (r = -0.97). Principal Component Analysis indicated positive correlations for phenolics, flavonoid levels and antiradical activity showing that all phenolic compounds are important for the scavenging activity of Brazilian propolis. The extract obtained with ethanol 30% v/v had the highest antiradical activity mainly due to its high content of dicaffeoylquinic acids.

Genome Mining of Endophytic Streptomyces wadayamensis Reveals High Antibiotic Production Capability

The actinobacteria Streptomyces wadayamensis A23, an endophitic strain, was recently sequenced and previous work showed qualitatively that the strain inhibits the growth of some pathogens. Herein we report the genome analysis of S. wadayamensis which reveals several antibiotic biosynthetic pathways. Using mass spectrometry, we were able to identify desferoxamines, several antimycins and candicidin, as predicted. Additionally, it was possible to confirm that the biosynthetic machinery of the strain when compared to identified known metabolites is far underestimated. As suggested by biochemical qualitative tests, genome encoded information reveals that the strain A23 has high capability to produce antibiotics.

Characterization of Royal Jelly by Electrospray Ionization Mass Spectrometry Fingerprinting

Royal jelly is an apicultural product, fed to the queen bee and consumed by humans as a health food and traditional medicine; its beneficial effects on human health have been the subject of several studies. As royal jelly is obtained in small amounts and reaches a high market price, it could be adultered with other cheaper substances. As it is prone to degradation at room temperature, lyophilization is used to prolong its shelf life. Due to the complex composition of royal jelly, several different parameters need to be evaluated to determine of freshness, purity and quality; consuming an appreciable amount of sample and time. Electrospray ionization mass spectrometry (ESI-MS) fingerprinting was carried out in the negative ion mode on a high resolution FT-ICR mass spectrometer; marker compounds were identified by comparison of their high resolution mass with data from literature. ESI-MS fingerprinting was capable of characterizing natural, lyophilized, degraded and adultered samples of royal jelly, and indicate marker compounds for each set of samples, with the aid of Principal Component Analysis. The complete analysis, from a simple extraction procedure to ESI (-)-MS fingerprinting, takes only a few minutes and consumes only 50 mg per sample. Therefore, large numbers of samples can be quickly evaluated for purity and freshness in a single-shot approach, while using small amounts of royal jelly per analysis.