Occurrence of zearalenone-4-beta-D-glucopyranoside in wheat

An LC-MS method was developed for the analysis of zearalenone-4-beta-D-glucopyranoside and zearalenone in wheat (Triticum aestivum). The limit of determination for zearalenone-4-beta-D-glucopyranoside and zearalenone was 10 microg/kg. The recovery rates were calculated to be 69% and 89% at a concentration of 100 microg/kg for zearalenone-4-beta-D-glucopyranoside and zearalenone, respectively. Twenty-four Bavarian wheat samples from a 1999 harvest were analyzed. Zearalenone was present in 22 of 24 field samples, the levels ranged from 11 to 860 microg/kg. Zearalenone-4-beta-D-glucopyranoside was found in 10 of the zearalenone positive samples (42%) at levels ranging from 17 to 104 microg/kg. The amounts of zearalenone-4-beta-D-glucopyranoside were correlated to those of zearalenone (r2 = 0.86, b = 0.10). After gastrointestinal hydrolyzation, zearalenone-4-beta-glucopyranoside might be implicated in the development of a zearalenone-syndrome. Therefore, more attention should be focused on conjugated mycotoxins in food and feed.     

Animal poxviruses transmitted from cat to man: current event with lethal end.

We report about the infection of an 18-year-old man with an orthopox virus (OPV) which was transmitted by a cat. The infectious route from cat to man could be proved by epidemiological, virological and serological methods. The corresponding techniques are described. The patient had not been vaccinated against smallpox and was intensively immunosuppressed by medication on account of a severe endogeneous eczema combined with an allergic asthma bronchiale. A cyclic poxvirus disease developed with a generalised, partly confluent pox virus exanthema disseminated over the body. The clinical symptoms were similar to a "variola pustulosa haemorrhagica". The young man died of a lung embolism in the course of the intensive medical therapy. The haemorrhagic character of the pox virus pustules with central necrosis (pox navel) could be reproduced in the rabbit skin and on chorioallantois membranes. The pox virus isolated from the patient could be differentiated from variola, vaccinia and monkeypox virus. It is a member of the group of "cowpox-like viruses". The environmental importance of these OPVs is discussed.     

Species-specific responses to environmental stress on germination and juvenile growth of two Bolivian Andean agroforestry species

Integrating native trees in farmland can support soil, water and biodiversity conservation. This is particularly important in regions characterized by long periods of drought and soil erosion, such as the Bolivian Andes, where agroforestry with native woody species is rarely applied. Better knowledge on the effects of environmental stress on propagation and establishment of such native plants is needed to optimize their cultivation. In our study, we tested the effects of temperature and scarification on seed germination, and assessed seedling survival and juvenile growth of two potential agroforestry species (Prosopis laevigata var. andicola, Schinus molle) under diverse soil and water conditions. Temperatures above 30 °C accelerated germination, but they increased fungi infestation in the case of S. molle. The application of acid and mechanical scarification significantly improved the germination capacity of P. laevigata var. andicola. Medium to high moisture levels in sand provided the most favourable conditions for plant growth. S. molle was more sensitive to dry and P. laevigata var. andicola more vulnerable to water-saturated clay loam. Mulching enhanced the survival and growth of S. molle juveniles, but increased P. laevigata var. andicola’s growth in sand and dry soils only. Our results may facilitate guidance on improving propagation of these two potential agroforestry species under environmental stress conditions. More generally, our study shows that easily applicable treatments, such as mulching, can significantly improve the cultivation of native species, provided that their habitat requirements and limiting factors are well known. This highlights the relevance of identifying and closing such knowledge gaps for native trees and shrubs in order to promote their potential for use in agroforestry.     

Metabolites of Monascus ruber in silages

A total of 233 silages were examined and found that Monascus ruber was present in 43 samples with counts between 1 × 10³ and 9 × 10⁶ colony-forming units (CFU)/g (mean: 2 × 10⁵ CFU/g). Monacolin K_L and the hydroxy acid monacolin K_A were detected by liquid chromatography-mass spectrometry in 45 and 50 of 233 samples at levels ranging from 25–15 600 and 28–65 400  μ g/kg, respectively. Citrinin was found with high-performance liquid chromatography-fluorescence detection (FLD) in 14 (6%) samples, the concentrations varied between 2.4 and 64.2  μ g/kg. The concentrations of citrinin were low and toxic effects are not anticipated. Monacolin K_A and monacolin K_L occur frequently and in considerable amounts in silages. These metabolites are believed to influence the metabolic activity of rumen anaerobic fungi resulting in a poorer digestion of crude fibre.     

Quantitative determination of beta-carotene stereoisomers in fresh, dried, and solar-dried mangoes (Mangifera indica L.)

A rapid method for quantitative determination of beta-carotene, including cis-isomers, in dried mango has been developed. Applicability of available methods to dried products was limited because of formation of artifacts caused by extraction and preparation. The analytical procedure was based on the extraction of carotenoids from dried mango mesocarp using a mixture of methanol and acetone/hexane, allowing the separation of disturbing fibers. No saponification was required. Furthermore, carotenoid determination by HPLC on a C30 stationary phase was achieved. This method was applied to determine beta-carotene and its stereoisomers in fresh, dried, and solar-dried mango slices of four cultivars. Drying resulted in a complete and partial degradation of xanthophylls and all-trans-beta-carotene, respectively. Isomerization was shown to depend on the drying process. Whereas conventionally dried mangoes were characterized by elevated amounts of 13-cis-beta-carotene, solar-dried mango slices contained additional amounts of the 9-cis-isomer. Calculation of vitamin A values was based on the real amount of the beta-carotene stereoisomers and ranged from 113 to 420 and from 425 to 1010 RE/100 g for fresh and dried mango slices, respectively.     

Proanthocyanidins: target compounds as antibacterial agents

Grape seeds accumulate in huge quantities as byproduct during wine production and are therefore a cheap source for pharmacologically active agents. However, studies prove poor antibacterial activity, and results of analyses are sometimes contradictory. The aim of this study was, thus, to determine the antibacterial activity of grape seed extracts with special focus on the chromatographic characterization of active fractions. In the course of these investigations, extraction protocols were optimized so that microwave-assisted extraction (MAE) guaranteed highest preconcentration efficiency. Proanthocyanidins, monomeric flavonoid aglycones, as well as some of their glycosides could be identified within yielded extracts via high-performance liquid chromatography-mass spectrometry (HPLC-MS). By that means the coherence number of possible isomers of procyanidins was approximated by a newly developed equation. As far as antibacterial activity determined via screening tests is concerned, the extracts generally have been found to be positively responsive toward 10 different gram-positive and gram-negative bacteria strains. After fractionation of the raw extracts, proanthocyanidins P2, P3, P4 and gallate esters P2G and P3G (P = proanthocyanidin consisting of catechin and epicatechin units, n = oligomerization degree, G = gallate ester) were determined as active antibacterial agents toward 10 different pathogens. Only moderate activity was found for monomeric flavonoid fractions.     

Agroforestry species of the Bolivian Andes: an integrated assessment of ecological, economic and socio-cultural plant values

Agroforestry is a promising method for enhancing land-use sustainability in the Bolivian Andes. However, its benefits in terms of rural development are under-recognized due to gaps in understanding users?? perceptions while taking into consideration both local and global environmental goals. Our study aimed to narrow these gaps by developing an analytical framework for analyzing the site-specific socio-ecological factors and interactions related to local woody species and assessing their ecological, economic, and socio-cultural plant values in order to identify the most promising agroforestry species. The framework was then tested in an indigenous community at 2,760?C3,830?m?a.s.l., incorporating vegetation surveys, environmental studies, and interviews on plant functions. Ecological, economic, and socio-cultural values and the ecological apparency of plants were calculated, and detrended correspondence and principal component analyses helped to reveal the socio-ecological context of significant factors for plant distribution and uses. Results showed dominating seral woody species along an altitudinal gradient. Although shrubs were more ecologically apparent than trees, trees were perceived to be more valuable as the usefulness and cultural importance of species increased with plant height and timber availability. Phytosociological factors played a minor but still significant role in perceived usefulness. Schinus molle and Prosopis laevigata (<3,200?m a.s.l.), Polylepis subtusalbida (>3,200?m a.s.l.), and Baccharis dracunculifolia (both zones) were evaluated as most promising for agroforestry use. In conclusion, our analytical framework proved to be a valuable tool for context-specific agroforestry plant selection. Nonetheless, economic, technical, and socio-cultural limitations of cultivating native agroforestry species were revealed as well. Agroforestry science and practice should, therefore, focus on enhancing reproductive potentials of existing woody vegetation, as well as problem-oriented horizontal dialogues between indigenous, expert, and scientific actors.     

Variation of seed mass and its effects on germination in <Emphasis Type="Italic">Polylepis australis</Emphasis>: implications for seed collection

South American Polylepis mountain forests are recognised as being one of the most endangered forest ecosystems in the world. Reforestation measures have been strongly recommended but may be hampered due to the very low seed germination reported for several Polylepis species. In order to facilitate reforestation we analysed the influence of seed mass on germination probability for Polylepis australis seeds in the Córdoba mountains (central Argentina). We collected seeds from 43 trees distributed throughout five woodland fragments located within two regions differing in size, topographical position, and altitude (1,900 m a.s.l. and 2,200 m a.s.l.). Seeds of Polylepis australis exhibited a great variation in terms of mass and percent seed germination among individual trees and among geographical regions. The results of logistic regression showed that germination probability was highly correlated with seed mass. However, the explained deviance significantly increased by including the region, the woodland fragment and especially the individual tree in addition to seed mass in the regression models. We conclude that selecting seeds on the basis of mass is an appropriate way to enhance germination prospects for reforestation projects. However, no absolute mass values are applicable in this context as the highest germination probabilities were reached at varying seed mass values depending on geographical region, woodland fragment or individual tree. We suggest collecting the relatively heaviest available seeds, even though the absolute seed mass may be low.