22 research outputs found
The specific chemical profile of Mediterranean propolis from Malta
Seventeen Maltese propolis samples were studied by GCâMS after silylation. They exhibited the typical
Mediterranean chemical profile, rich in diterpene compounds (18â92% of TIC, GCâMS): 32 individual
diterpenes were identified; 22 of them were present in each specimen. The other abundant compound
group was that of sugars and sugar derivatives. In some samples, however, another compound group
was observed (0â12% of TIC, GCâMS); the corresponding mass spectra were consistent with monoand
sesquiterpenyl esters of substituted benzoic acids. Two new propolis constituents of this group, daucane
diterpene esters of hydroxybenzoic acids, were isolated. Their origin is suggested to be Ferula communis,
as they are taxonomic markers for this species. All propolis samples were active against
Staphylococcus aureus but only those with high concentrations of terpenyl esters showed antifungal activity
against Candida albicans. The present results confirm that Mediterranean propolis is a valuable natural
product with potential to improve human health.peer-reviewe
Different extraction methods of biologically active components from propolis: a preliminary study
Abstract Background Propolis is widely used in apitherapy, preparations, and food and beverage additives. Various extraction techniques were applied in the extraction of the biologically active constituents of poplar type propolis in order to compare their efficiency. The methods employed were: traditional maceration extraction, ultrasound extraction (UE), and microwave assisted extraction (MAE). Results The total amounts of extracted phenolics and flavonoids were determined, and the effectiveness of the methods compared. MAE was very rapid but led to the extraction of a large amount of non-phenolic and non-flavonoid material. UE gave the highest percentage of extracted phenolics. Conclusion Compared to the maceration extraction, MAE and UE methods provided high extraction yield, requiring short timeframes and less labour. UE was shown to be the most efficient method based on yield, extraction time and selectivity.</p
Bioactive Constituents of Brazilian Red Propolis
In a new propolis type, red Brazilian propolis, 14 compounds were identified (six of them new for propolis), among them simple phenolics, triterepenoids, isoflavonoids, prenylated benzophenones and a naphthoquinone epoxide (isolated for the first time from a natural source). Three of the major components demonstrated significant antimicrobial activity, and two (obtained as inseparable mixture) possessed radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH)
Assessing the performance of analytical methods for propolis â 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 methodsâ 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 ApĂıcola 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: âDivInA-Diversification and Innovation on
Beekeeping Productionâ. National funding by FCT â
Foundation for Science and Technology, through the institutional
scientific employment program-contract with
Soraia I. FalcĂŁo. 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
Antibacterial mono- and sesquiterpene esters of benzoic acids from Iranian propolis
<p>Abstract</p> <p>Background</p> <p>Propolis (bee glue) has been used as a remedy since ancient times. Propolis from unexplored regions attracts the attention of scientists in the search for new bioactive molecules.</p> <p>Results</p> <p>From Iranian propolis from the Isfahan province, five individual components were isolated: the prenylated coumarin suberosin <b>1</b>, and four terpene esters: tschimgin (bornyl <it>p</it>-hydroxybenzoate) <b>2</b>, tschimganin (bornyl vanillate) <b>3</b>, ferutinin (ferutinol <it>p</it>-hydroxybenzoate) <b>4, </b>and tefernin (ferutinol vanillate) <b>5</b>. All of them were found for the first time in propolis. Compounds <b>2 </b>- <b>5 </b>demonstrated activity against <it>Staphylococcus aureus</it>.</p> <p>Conclusions</p> <p>The results of the present study are consistent with the idea that propolis from unexplored regions is a promising source of biologically active compounds.</p
Identification of the plant origin of the botanical biomarkers of Mediterranean type propolis
Propolis is a honeybee product which bees produce by collecting resins from various botanical sources. The chemical composition of propolis is directly dependant on the availability of resinous plant materials in different geographic regions. This study was undertaken to evaluate the resinous plant sources used by bees to produce Mediterranean type propolis. Although this propolis type has already been the subject of numerous studies, its major botanical source had not yet been identified. In this study, using GC-MS analysis, we identify the resin of the common cypress, Cupressus sempervirens, as the major plant source of the characteristic diterpene fingerprint profile of Mediterranean propolis.peer-reviewe
Identification of the plant origin of the botanical biomarkers of Mediterranean type propolis
Propolis is a honeybee product which bees produce by collecting resins from various botanical sources. The chemical composition of propolis is directly dependant on the availability of resinous plant materials in different geographic regions. This study was undertaken to evaluate the resinous plant sources used by bees to produce Mediterranean type propolis. Although this propolis type has already been the subject of numerous studies, its major botanical source had not yet been identified. In this study, using GC-MS analysis, we identify the resin of the common cypress, Cupressus sempervirens, as the major plant source of the characteristic diterpene fingerprint profile of Mediterranean propolis.peer-reviewe
Preparation and characterization of UVâcurable acrylic membranes embedding natural antioxidants
We examine the behaviour of acrylic resinâbased membranes containing natural antioxidants, such as Galla Chinensis tea powder extract (TP) and Taiwanese green propolis (TGP), in different concentrations ranging between 5 and 20 wt %. Membrane morphology was investigated by means of Environmental Scanning Electron Microscopy (ESEM), while the UVâcuring reaction was monitored by FourierâTransform Infraâred (FTIR) spectroscopy. In most cases Thermogravimetric (TG), Differential Scanning Calorimetric (DSC) and Dynamoâmechanical Thermal (DMT) analyses showed that the desirable characteristics of the UVâcured acrylic resin are not substantially altered by the presence of the organic fillers. The release kinetics of polyphenols and flavonoids, determined in water for TPâcontaining membranes (ETx) and in ethanol/water mixture (7:3 v/v) for TGPâcontaining ones (EPx), was satisfactory, reaching a plateau after 24 h.
Finally, preliminary antibacterial tests against S. Epidermidis were performed on the membranes with higher additive amount and gave positive results for ETâtype; on the contrary, no inhibitory effect was observed for the tested EPâtype membranes