Urban honey - the aspects of its safety.

To contribute to the development of urban beekeeping, we designed this study to obtain more information about the contamination of urban bee products with toxic metals, polycyclic aromatic hydrocarbons (PAHs), and pesticides. The samples of honey (N=23), pollen (N=13), and floral nectar (N=6) were collected from the experimental stationary apiary of the Belgrade University Faculty of Agriculture located in centre of Zemun (a municipality of the Belgrade metropolitan area) in 2015 and 2016. Metals (Pb, Cd, As, Cu, Zn, Fe, Mn, Ni, Cr, and Hg) were determined with inductively coupled plasma quadrupole mass spectrometry (ICP-QMS). Polycyclic aromatic hydrocarbons (PAHs) were analysed with high-performance liquid chromatography with fluorescence detection (HPLC-FLD). Pesticides were analysed with gas chromatography - mass spectrometry (GC-MS). The honey samples were generally within the European and Serbian regulatory limits. The levels of all the 123 analysed pesticides were below the limit of quantification (LOQ). Regarding PAH levels in honey, the highest content was found for naphthalene. The elevated levels of Hg and Cr and of PAHs in the pollen samples indicated air pollution. Pesticide residues in pollen, however, were below the LOQ. In nectar, metal levels were relatively similar to those in honey. Our results suggest that the investigated urban honey meets the regulatory requirements for metals, PAHs, and pesticides and is therefore safe for consumption.

Applying multi-criteria analysis for preliminary assessment of the properties of alginate immobilized Myriophyllum spicatum in lake water samples.

The preliminary assessment of the properties of alginate immobilized aquatic weed Myriophyllum spicatum beads-MsAlg in a multi-element system of nine Serbian lakes water samples was done. Herein, the results obtained in the biosorption experiment with MsAlg contents of twenty-two elements analysed by inductively coupled plasma-optical emission spectrometry, biosorption capacity, element removal efficiency, total hardness (TH) and quality index of water (WQI) are presented. Scanning electron microscopy with energy dispersive X-ray spectroscopy was used for the characterization of M. spicatum and its beads. The study showed that aluminium, magnesium and strontium were adsorbed by MsAlg in the water samples from all examined lakes; barium and iron in the water samples from six lakes. The overall average efficiency of MsAlg in biosorption of elements was in the following order: Al > Ba > Sr > Fe > Mg (58.6, 51.7, 48.2, 23.9 and 17.7%, respectively). The increase of TH and WQI values after the biosorption was noticed in all studied lake water samples. The most significant correlations for pH were regarding the contents of B, Mg and Ca, whereas WQI was highly correlated to the contents of B and Mg, and pH. The complexity of the obtained data was explained by Cluster Analysis and Principal Component Analysis, which showed good discrimination capabilities between the water samples taken from different locations. Considering that the invasive M. spicatum is natural, widespread and that its immobilization is cheap and eco-friendly, presented findings could be helpful in further assessment of MsAlg beads for its potential use as biofilter.

Neuroprotective Potential and Chemical Profile of Alternatively Cultivated Ganoderma lucidum Basidiocarps.

Various neurodegenerative diseases are the main challenges to the modern medicine and there is a great need for novel, natural, neuroprotective agents. Ganoderma lucidum is a well-known medicinal mushroom, which health benefits have been confirmed by numerous studies. As demand for its basidiocarps is increased and traditional cultivation on hardwoods is not environmentally friendly and economically justified, finding of alternative substrates is necessary. The aim of the study was to assess the effect of alternative cultivation substrates on the chemical profile of G. lucidum basidiocarps and their capacity to inhibit acetylcholinesterase and tyrosinase, which higher activity is directly associated with neurodegenerative processes. Extracts of basidiocarps cultivated on alternative substrates, especially on clear wheat straw, showed significantly higher inhibition capacities than extracts of commercially-grown ones. These extracts were considerably different chemically from commercial basidiocarps extracts and even nine new compounds were isolated from them. Our results suggest that cultivation substrate greatly affect the chemical profile and neuroprotective capacity of obtained basidiocarps and wheat straw is a promising cultivation substrate.

Determination of trans- and cis-resveratrol in Serbian commercial wines.

Resveratrol (trans-3,5,4'-trihydroxystilbene) is a phytoalexin produced by grapevines in response to fungal infection, particularly to Botrytis cinerea. It has been shown that it possess various biological effects such as prevention of cardiovascular diseases and anti-inflammatory and anticancerogenic properties. Red wines are a primary source of resveratrol. Although a number of investigations have focused on the determination of resveratrol in wines of different countries, there is no similar study about the wines produced in Serbia. As authors are aware, the only study concerning resveratrol content in wine in the Balkan region was conducted in Greece. In this study, the trans- and cis-resveratrol content in samples obtained from 18 commercial Serbian wines (10 red, 7 white, and 1 rose) were analyzed. Analyses were performed after solid-phase extraction by high-performance liquid chromatography with a diode array detection system using an RP-C(18) column with gradient elution [solvent A: acetonitrile-acetic acid-water (20:2:78 v/v), solvent B: acetonitrile-acetic acid-water (90:2:8 v/v)]. Detection of trans- and cis-resveratrol was performed on 306 and 286 nm, respectively. It was clearly established that there was a presence of trans-resveratrol isomers in all analyzed wines (0.11-1.69 mg/L) except in one white wine. Cis-resveratrol was present in 12 from 18 samples in different amounts (0.12-1.49 mg/L).

Different intermolecular interactions in azido[2-(diphenylphosphino)benzaldehyde semicarbazonato-kappa2P,N1,O]nickel(II).

The title compound, [Ni(C(20)H(17)N(3)OP)(N(3))], is the first complex with a semicarbazide-based ligand having a P atom as one of the donors. The influence of the P atom on the deformation of the coordination geometry of the Ni(II) ion is evident but less expressed than in the cases of complexes with analogous seleno- and thiosemicarbazide ligands. The torsion angles involving the two bonds formed by the P atom within the six-membered chelate ring have the largest values [C-P-Ni-N = 24.3 (2) degrees and C-C-P-Ni = -24.2 (4) degrees ], suggesting that the P atom considerably influences the conformation of the ring. Two types of N-H...N hydrogen bond connect the complex units into chains.

Transition metal complexes with thiosemicarbazide-based ligands. LIII. [4-(2-Diphenylphosphino-alpha-ethoxybenzyl-kappaP)-S-methyl-1-(4-oxidopent-3-en-4-ylidene-kappaO)thiosemicarbazido-kappa(2)N(1),N(4)]nickel(II).

The title compound, [Ni(C(28)H(30)N(3)O(2)PS)], crystallizes with two independent molecules in the asymmetric unit. The Ni(II) atoms are in significantly deformed square-planar environments formed by an ONNP donor set from a thiosemicarbazide-based tetradentate ligand. The Ni(II) atom and the ONN donor atoms are nearly coplanar, while the P atom deviates from their mean planes by 0.278 (4) and 0.202 (4) Angstrom for the two independent molecules. The P-containing chelate rings are remarkably non-planar, adopting a boat conformation, which is unusual for chelate rings in transition metal complexes with thiosemicarbazide-based tetradentate ligands. The orientation of the ethoxy group bonded to this chelate ring is caused by an intramolecular C-H...pi interaction with the opposing phenyl ring. There are no hydrogen bonds; instead, numerous intermolecular C-H...pi interactions dominate in the crystal packing.