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.129739-4

Assessing the performance of analytical methods for propolis – A collaborative trial by the international honey commission

Propolis is a resinous beehive product with extraordinary bioactivity and chemical richness, linked with the botanical sources of the resin. The potential of this product keeps captivating the scientific community, conducting to continuous and growing research on plant sources, composition, or applications in agriculture, cosmetics, pharmacy, odontology, etc. In all cases, the quality assessment is a requirement and relies on methods to extract the bioactive substances from the raw propolis and quantify different components. Unfortunately, besides the absence of international quality requirements, there is also a lack of standardized analytical procedures, despite the presence of several methodologies with unknown reliability, often not comparable. To overcome the current status, the International Honey Commission established an inter-laboratory study, with propolis samples from around the globe, to harmonize analytical methods and evaluate their accuracy. A common set of protocols was matched between twelve laboratories from nine countries, for quantification of ash, wax, and balsamic content in raw propolis, and spectrophotometric evaluation of total phenolics, flavone/flavonol, and flavanone/ dihydroflavonol in the extract. A total of 3428 results (97% valid data), were used to assess the methods’ accuracy following ISO-5725 guidelines. The within-laboratory precision, revealed good agreement levels for the majority of the methods, with relative variance below 5%. As expected, the between-laboratory variance increased, but, with exception of the flavanone method that revealed a clear lack of consistency, all the others maintained acceptable variability levels, below 30%. Because the performance of ultrasounds procedures was low, they cannot be recommended until further improvements are made.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support by national funds FCT/MCTES to CIMO (UIDB/00690/2020). Thanks to the Programa Apíıcola Nacional 2020-2022 (National Beekeeping Program) for funding the project "Standardization of production procedures and quality parameters of bee products" and to Project PDR2020-1.0.1- FEADER-031734: “DivInA-Diversification and Innovation on Beekeeping Production”. National funding by FCT – Foundation for Science and Technology, through the institutional scientific employment program-contract with Soraia I. Falcão. A special thanks is given to Hartmut Scheiter and Allwex Food Trading GmbH, Bremen, Germany, for providing, handling and delivering the propolis blind samples.info:eu-repo/semantics/publishedVersio

Propolis: recent advances in chemistry and plant origin

New information published since 1995 about propolis constituents is reviewed. The available information on the biological action of new found components is presented. Recent publications are reviewed on propolis of native South American stingless bees. The plant sources of bee glue are discussed, taking into consideration data based on reliable chemical evidence including comparisons between propolis samples and plant material. Some aspects of the chemical standardization of propolis are discussed.Récents progrès dans la chimie de la propolis et son origine végétale. La propolis est un matériau multifonctionnel utilisé par les abeilles pour la construction et la maintenance de leurs ruches. Elle est utilisée par l'Homme depuis longtemps. En raison de ses activités biologiques variées et précieuses, la propolis est actuellement utilisée en apithérapie et comme composant des cosmétiques et des " produits de santé ". L'article discute des plantes qui fournissent la propolis. Pour cela on utilise les données qui reposent sur des connaissances chimiques fiables et qui comportent des comparaisons entre échantillons de propolis et matériel végétal. La principale source de propolis dans la zone tempérée est l'exsudat des bourgeons de peuplier (Populus spp.) ; dans le Nord de la Russie, c'est l'exsudat de bouleau (Betula verrucosa). Quelques informations sont données concernant les sources de propolis en Australie (Xanthorrhoea spp.) et au Brésil (Araucaria spp., Baccharis spp.). L'article fait le point sur les constituants nouveaux de la propolis publiés après 1994 et non inclus dans le dernier article de synthèse de Marcucci [31] paru en 1995. Le tableau I donne la liste de ces nouveaux constituants et la figure 1 présente quelques structures chimiques. L'activité biologique des nouveaux constituants est indiquée dans le tableau II. Les récentes analyses concernant la composition de la propolis des abeilles sans aiguillon indigènes d'Amérique du Sud sont également passées en revue. La composition chimique complexe et variable de la propolis crée un sérieux problème pour son utilisation médicale. Les principales difficultés sont liées à l'absence de tout contrôle concernant l'origine et de l'origine dépend la composition. La connaissance par l'analyse chimique de composés actifs pourrait conduire à la formulation d'un certain nombre de standards " locaux "basés sur l'origine botanique, comme par exemple un standard " européen ", un standard " de Russie septentrionale "ou différents standards " brésiliens ". Le tableau III donne les constituants les plus typiques de la propolis de diverses origines géographiques et leur origine végétale

Phenolics from Brazilian propolis

The main phenolic constituents from Brazilian propolis, originating from Sao Paulo State, were isolated and identified: three flavonoids, a prenylated coumaric acid and two new benzopyranes, E and Z 2,2-dimethyl-6-carboxyethenyl-8-prenyl-2H-benzopyranes

Chemical characteristics of poplar type propolis of different geographic origin

Validated spectrophotometric procedures were used to quantify three main groups of bioactive substances (phenolics, flavones/flavonols, flavanones/dihydroflavonols) in 114 samples of poplar-type propolis from different geographic origins. From the results, we characterized raw poplar propolis in terms of minimum content of its bioactive components (antimicrobial and antioxidant) as follows: 45% resin, 21% total phenolics, 4% total flavones/flavonols; 4% total flavanones/dihydroflavonols, and a maximum Minimum Inhibitory Concentration (MIC) against S. aureus of 250 $\mu$g/mL. A significant negative correlation was observed between the amount of total phenolics and MIC. The results indicate that measuring the concentrations of groups of active compounds, rather than individual components, is an appropriate approach in developing quality standards for propolis

Natural antioxidants in emulsions O/W

This study compared the capacity of propolis extract (PE) and thyme waste extract (TWE) to prevent the oxidation of oil in water (O/W) emulsion, as well as their impact on emulsion apparent viscosity (AV) in the presence of wheat germ and almond oils as lipid phase. For this, central composite design (CCD) and principal component analysis (PCA) were performed. Oxidation process was monitored by evaluating the formation of primary and secondary lipid oxidation products, at the same time the AV behavior was determined evaluating consistency index and flow behavior index. The results revealed that the increase of PE% and TWE% decreases TBARS (Thiobarbituric Acid Reactive Substances) and hydroperoxides formation. Viscosity increases with the rise of TWE% over (0.04%), whereas lower concentrations of PE% decreases it. Those results have been confirmed in the PCA analysis. TWE showed higher resistance to oxidation, although PE was more effective as antioxidant than TWE.UIDB/05183/2020info:eu-repo/semantics/acceptedVersio