Leaf-cutting ants toxicity of limonexic acid and degraded limonoids from Raulinoa echinata. X-ray structure of epoxy-fraxinellone

Phytochemical survey of roots extracts of the South Brazilian endemic plant Raulinoa echinata Cowan, Rutaceae led to the isolation of known degraded limonoids: fraxinellone, fraxinellonone and epoxy-fraxinellone. The latter was previously isolated also from the stems, but the relative configuration could not be solved by NMR experiments. This paper deals with the X-ray diffraction analysis of epoxy-fraxinellone and its toxicity to leaf-cutting ants, describes the isolation of fraxinellonone and fraxinellone for the first time in Raulinoa. Epoxy-fraxinellone showed no toxicity to the leaf-cutting ants (Atta sexdens rubropilosa). The limonoid limonexic acid, isolated from stems, presented high toxicity to the leaf-cutting ants, diminishing considerably their longevity. ©2005 Sociedade Brasileira de Química.

Search for associated Higgs boson production WH→WWW *→l±νl′±ν′+X in pp̄ collisions at s=1.96TeV

We present a search for associated Higgs boson production in the process pp̄→WH→WWW*→l±νl′±ν′ +X in final states containing two like-sign isolated electrons or muons (e±e±, e±μ±, or μ±μ±). The search is based on D0 run II data samples corresponding to integrated luminosities of 360-380pb-1. No excess is observed over the predicted standard model background. We set 95% C.L. upper limits on σ(pp̄→WH) ×Br(H→WW*) between 3.2 and 2.8 pb for Higgs boson masses from 115 to 175 GeV. © 2006 The American Physical Society.