Chemical Composition of Volatile and Extractive Organic Compounds in the Inflorescence Litter of Five Species of Woody Plants.

The decomposition of plant litter, most of which is found in forests, is an important element of the global carbon cycle, as a result of which carbon enters the atmosphere in the form of not only CO2 but also volatile organic compounds (VOCs). Although the formation of litter is associated with autumn cooling, in the spring, there is a very intense fall of faded inflorescences of woody plants. This study examined the chemical composition of the litter and VOCs emitted from decaying inflorescences of four species of forest-forming trees: silver birch, European hornbeam, black alder and aspen. All litter emissions consisted of 291 VOCs, mainly terpenes actively participating in atmospheric processes. The detection of a number of typical mushroom metabolites, such as 1-octen-3-ol, known as "mushroom alcohol", and alkyl sulphides, suggests that inflorescence-derived VOCs are a mixture of components of plant and microbial origin. In methanol extracts of the fallen inflorescences of all types, 263 organic compounds were identified, the majority of which were related to carbohydrates. Their share in the extracts was 72-76%. In general, the composition of the extractive compounds indicates the easy availability of this material for assimilation by various types of destructors.

Chemical Composition and Biological Activity of Argentinian Propolis of Four Species of Stingless Bees.

The chemical composition of propolis of four species of stingless bees (SLBs) from Argentina was determined, and its antibacterial and anticancer activity was evaluated on selected types of microbes and cancer cell lines. Volatile secretions of all propolis samples are formed by 174 C2-C15 organic compounds, mainly mono- and sesquiterpenes and their derivatives. The chromatograms of ether extracts showed 287 peaks, of which 210 were identified. The most representative groups in the extracts of various propolis samples were diterpenoids (mainly resin acids), triterpenoids and phenolic compounds: long-chain alkenyl phenols, resorcinols and salicylates. The composition of both volatile and extractive compounds turned out to be species-specific; however, in both cases, the pairwise similarity of the propolis of Scaptotrigona postica and Tetragonisca fiebrigi versus that of Tetragona clavipes and Melipona quadrifasciata quadrifasciata was observed, which indicated the similarity of the preferences of the respective species when choosing plant sources of resin. The composition of the studied extracts completely lacked flavonoids and phenolcarboxylic acids, which are usually associated with the biological activity and medicinal properties of propolis. However, tests on selected microbial species and cancer cell lines showed such activity. All propolis samples tested against Paenibacillus larvae, two species of Bacillus and E. coli showed biofilm inhibition unrelated to the inhibition of bacterial growth, leading to a decrease in their pathogenicity. Testing the anticancer activity of ether extracts using five types of cell cultures showed that all four types of propolis studied inhibit the growth of cancer cells in a dose- and time-dependent manner. Propolis harvested by T. clavipes demonstrated the highest cytotoxicity on all tested cell lines.

[Determination of the thyreostats in animal muscle tissue by matrix solid-phase dispersion (MSPD) and liquid chromatography-tandem mass spectrometry]. / Zastosowanie metody ekstrakcji rozpraszania próbki w fazie stalej (MSPD) do oznaczania tyreostatyków w tkance miesniowej zwierzat metoda chromatografii cieczowej-tandem spektometrii mas.

BACKGROUND: The residues ofthyreostats must not be present in the edible animal tissues. The proposed in the EU minimum required performance limit (MPRL) in the animal tissues is 10 microg/kg. This implies the decision limit (CCalpha) and decision capability (CCbeta) of the analytical methods used for the determination of these compounds lower than 10 microg/kg. OBJECTIVE: This study aimed at the development, basing on the literature data and own studies the analytical method allowing for the identification and quantification of five thyreostats: tapazole (TAP), thiouracil (TU), methylotiouracil (MTU), propylothiouracil (PTU) and phenylotiouracil (FTU)) in the bovine muscle tissue, which would meet the criteria set in the Commission Decision No 2002/657/EC. MATERIAL AND METHODS: The developed method used liquid chromatography-tandem mass spectrometry (LC-MS/MS). The sample was extracted and cleaned using the matrix solid-phase dispersion (MSPD) method. The LC was equipped with column Luna C18 Phenomenex. Dimetylotiouracyl was used as internal standard. The samples were fortified at levels: 5, 10 and 20 microg/kg. The method was validated according to the criteria laid down in Commission Decision No. 2002/657/EC. RESULTS: At the levels, mean relative recoveries was in the range 90 - 109% and repeatability (CV %) was less than 10%. Decision limit (CCalpha) and detection capability (CCbeta) calculated for all thyreostats were below the recommended minimum required performance limit (MRPL) - 10 microg/kg. CONCLUSIONS: The developed and validated LC-ESI-MS/MS method allows for the identification and quantification of five thyreostats in the bovine muscle tissue in the quantities below 10 microg/kg. Analytical procedure meets the criteria of Commission Decision No 2002/657/EC.

[Determination of malachite green and leukomalachite green residues in fish muscle by high-performance liquid chromatography method]. / Oznaczanie pozostalosci zieleni malachitowej i leukomalachitowej w tkance miesniowej ryb metoda wysokosprawnej chromatografii cieczowej.

Malachite green (MG) and leukomalachite green (LMG) are subjected to monitoring fish muscle, with a minimum required performance limit (MRPL) set 2 microg/kg. Samples were extracted with acetonitryle-buffer mixture and cleaned up on SCX solid phase extraction (SPE) column. LC separation MG and LMG was done on column Luna Phenyl-Hexyl Phenomenex. Samples were fortified with MG and LMG between 2 - 25 microg/kg. The coefficients of variation (CV%) were lower than 14% for MG and 16%for LMG. The mean recoveries were in the range 65- 83% for MG and 70- 73% for LMG. This method fulfils the criteria for identification and determination of MG andLMG residues in the samples of fish muscle.