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

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

Bioassay guided purification of the antimicrobial fraction of a Brazilian propolis from Bahia state

<p>Abstract</p> <p>Background</p> <p>Brazilian propolis type 6 (Atlantic forest, Bahia) is distinct from the other types of propolis especially due to absence of flavonoids and presence of other non-polar, long chain compounds, but presenting good <it>in vitro </it>and <it>in vivo </it>antimicrobial activity. Several authors have suggested that fatty acids found in this propolis might be responsible for its antimicrobial activity; however, so far no evidence concerning this finding has been reported in the literature. The goals of this study were to evaluate the antibacterial activity of the main pure fatty acids in the ethanolic extract and fractions and elucidate the chemical nature of the bioactive compounds isolated from Brazilian propolis type 6.</p> <p>Methods</p> <p>Brazilian propolis type 6 ethanolic extract (EEP), hexane fraction (H-Fr), major fatty acids, and isolated sub-fractions were analyzed using high performance liquid chromatography (HPLC), high resolution gas chromatography with flame ionization detection (HRGC-FID), and gas chromatography-mass spectrometry (GC-MS). Three sub-fractions of H-Fr were obtained through preparative HPLC. Antimicrobial activity of EEP, H-Fr, sub-fractions, and fatty acids were tested against <it>Staphyloccus aureus </it>ATCC 25923 and <it>Streptococcus mutans </it>Ingbritt 1600 using minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC).</p> <p>Results</p> <p>EEP and H-Fr inhibited the growth of the microorganisms tested; nevertheless, no antimicrobial activity was found for the major fatty acids. The three sub-fractions (1, 2, and 3) were isolated from H-Fr by preparative HPLC and only sub-fraction 1 showed antimicrobial activity.</p> <p>Conclusion</p> <p>a) The major fatty acids tested were not responsible for the antimicrobial activity of propolis type 6; b) Sub-fraction 1, belonging to the benzophenone class, was responsible for the antimicrobial activity observed in the present study. The identification of the bioactive compound will improve the development of more efficient uses of this natural product.</p

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