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The antiherpes effects of the crude extract obtained from Ilex paraguariensis leaves (yerba mate) and their purified fractions were investigated. The most active fraction was selected and assayed to determine the viral multiplication steps upon which it acted. In order to detect the major components of this fraction, thin layer chromatography (TLC) analysis was performed. The antiviral activity was evaluated against HSV-1 and HSV-2 by a viral plaque number reduction assay (IC(50) ) and the cytotoxicity by a MTT assay (CC(50) ). According to the obtained results, all tested samples showed antiherpes activity at noncytotoxic concentrations, and the ethyl acetate fraction was the most active (SI = CC(50) /IC(50) = 188.7 and 264.7 for HSV-1 and HSV-2, respectively). The results also demonstrated that this fraction exerts antiviral activity by the reduction of viral infectivity, the inhibition of virus entry into cells and cell-to-cell virus spread, as well as by the impaired levels of ICP27, ICP4, gD and gE proteins of HSV-1. The TLC analysis showed that this fraction contains monodesmosidic triterpenoid saponins, matesaponin-1 (a bidesmosidic one), caffeic and chlorogenic acids and rutin, which suggests that they could act synergistically and be responsible for the detected antiherpes activity.

Arabidopsis thaliana is commonly regarded as a self-pollinated plant species. One of the many surprises in population genetic studies of the species was the observation of distinct traces of recombination in the DNA sequences that may be the result of rare outcrossing events. We studied flower visitors in a natural population of the species. Solitary bees, diptera and thrips are among the most frequently observed insects among the surprising diversity of insects visiting flowers of A. thaliana. Assuming that every visit equals an outcrossing event, the outcrossing rate was estimated to be 0.84 %. This value falls between estimations of outcrossing rates from molecular data and those of artificial systems. Despite the rather low rate of flower visitation, A. thaliana can no longer be regarded as a completely self-pollinated plant species in the wild. This observation may explain recombination events observed in molecular analyses. Possible pollen transfer between populations due to the mobility of the observed insects should be considered in population genetic analyses.

An interactive key is described for larvae and adults of economically important species of thrips. This is based on computerized photographs (Automontage), video clips and an interface to a molecular key for larvae based on ITS-RFLP analysis.

Using energetic considerations, ketonic structures are postulated for the [Molefin]+ fragments derived from alkoxybenzenes, alkylthiobenzenes and 9-ethoxyanthracene. Experimentally determined heats of formation for the tautomeric molecular ions derived from anthrone and 9-anthrol differ by 37 Kcal. mole−1.

Die Dichte des Quarzes nimmt bei starkem Reiben um etwa 10% ab. Diese Dichteabnahme ist zuruckzufuhren auf die Bildung von Hohlkanalen beim Reiben, welche aber merkwurdigerweise die Oberflache nicht erreichen. Durch die Zerteilung beim Reiben wird die Umwandlung des Quarzes behindert. Die Dichten des Cristobalits und des Quarzglases nehmen beim Reiben im Gegensatz zu der des Quarzes nicht ab, sondern urn etwa 2% zu.

Die aus den Nitropyrimidinen (I) mit Methoxidionen gebildeten Komplexe (II) und (III) werden NMR- und UV-spektroskopisch untersucht und mit den Trinitroanisolkomplexen (IV) verglichen.