Occurrence of mycotoxins in feed as analyzed by a multi-mycotoxin LC-MS/MS method.

Crops used for animal feed can be easily contaminated by fungi during growth, harvest, or storage, resulting in the occurrence of mycotoxins. Because animal feed plays an important role in the food safety chain, the European Commission has set maximum levels for aflatoxin B1 and recommended maximum levels for deoxynivalenol, zearalenone, ochratoxin A, and the sum of fumonisin B1 and B2. A multimycotoxin LC-MS/MS method was developed, validated according to Commission Decision 2002/657/EC and EN ISO 17025 accredited for the simultaneous detection of 23 mycotoxins (aflatoxin-B1, aflatoxin-B2, aflatoxin-G1, aflatoxin-G2, ochratoxin A, deoxynivalenol, zearalenone, fumonisin B1, fumonisin B2, fumonisin B3, T2-toxin, HT2-toxin, nivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, diacetoxyscirpenol, fusarenon-X, neosolaniol, altenuene, alternariol, alternariol methyl ether, roquefortine-C, and sterigmatocystin) in feed. The decision limits of the multimycotoxin method varied from 0.7 to 60.6 microg/kg. The apparent recovery and the results of the precision study fulfilled the performance criteria as set in Commission Decision 2002/657/EC. The analysis of three different feed matrices (sow feed, wheat, and maize) provided a good basis for the evaluation of the toxin exposure in animal production. In total, 67 samples out of 82 (82%) were contaminated; type B-trichothecenes and fumonisins occurred most often. The majority of the infected feed samples (75%) were contaminated with more than one type of mycotoxin.

Free radical generation assays: new methodology for accelerated oxidation studies at low temperature in complex food matrices.

A novel method for the rapid screening of antioxidant efficacy and oxidative stability in food and feed matrices has been developed. The analyses are described as free radical generation (FRG) assays. The new procedure combines the use of azo-initiators with analytical equipment that is widely used for antioxidant research such as the oxidative stability instrument and the oxygen bomb. The use of initiators instead of high temperatures as a driving force to increase the rate of oxidation improves the correlation between the accelerated screening of foodstuffs and real shelf life. The improved correlation can be mainly explained by the fact that food products are analyzed in their original status, maintaining all interfacial phenomena of the food matrix. Furthermore, the lower temperature of analysis reduces differences between the reaction kinetics of the assay and those of the oxidation during actual shelf life. Consequently, the correlation between the accelerated analysis and shelf life is improved, particularly when compared to accelerated oxidation at high temperatures. The FRG assays could be used successfully to evaluate the efficacy of natural antioxidants in heat-sensitive food products such as emulsions and meat products. A good correlation was observed between the accelerated tests and the oxidation parameters obtained from standard shelf-life evaluation. It was possible to successfully compare the efficacy of several antioxidants and to predict shelf life for these heat-sensitive food matrices.

Antileishmanial activity, cytotoxicity and QSAR analysis of synthetic dihydrobenzofuran lignans and related benzofurans.

A series of synthetic dihydrobenzofuran lignans and related benzofurans were evaluated for their cytotoxicity in a screening panel consisting of various human tumour cell lines, and for their antiprotozoal activity against L. donovani (axenic amastigotes), chloroquine resistant Plasmodium falciparum (strain K1), Trypanosoma brucei rhodesiense and T. cruzi, and for cytotoxicity on L6 cells. No promising cytotoxicities against human tumour cell lines were observed for newly synthesised compounds, but the dimerisation product of some lipophylic esters of caffeic acid, such as compound 2g, showed a high activity against chloroquine-resistant P. falciparum (strain K1) (IC50 0.43 microg/mL) and L. donovani (axenic amastigotes) (IC50 0.12 microg/mL), which was confirmed in an infected macrophage assay (IC50 0.19 microg/mL). QSAR models for the cytotoxic and antileishmanial activity were generated using Quasar receptor surface modelling.

Antiangiogenic activity of synthetic dihydrobenzofuran lignans.

A series of synthetic dihydrobenzofuran lignans, obtained by biomimetic oxidative dimerization of caffeic or ferulic acid methyl ester followed by derivatization reactions, was tested for its antiangiogenic activity in the CAM (chorioallantoic membrane) assay. The dimerization product of caffeic acid methyl ester (2a) (methyl (E)-3-[2-(3,4-dihydroxyphenyl)-7-hydroxy-3-methoxycarbonyl-2,3-dihydro-1-benzofuran-5-yl]prop-2-enoate) showed a pronounced antiangiogenic activity, especially the 2R,3R-enantiomer.