Prenylated p-Hydroxyacetophenone Derivatives from the Giant Senecio johnstonii

The extract of the aerial parts of S. johnstonii afforded five known prenylated p-hydroxyacetophenone derivatives, scopoletin and 5-pentadecyl resorcinol together with the tridecyl derivative. The chemotaxonomic situation is discussed briefly.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28519/1/0000316.pd

SESQUITERPENE LACTONES FROM PERITYLE EMORYI

Abstract-The extract of the aerial parts of Perityle emoryi gave, in addition to seven known sesquiterpene lactones, six new germacranolides and a guaianolide as well as a further thymol derivative together with several known ones and two labdanes. The structures were elucidated by high field 'H NMR spectroscopy. The chemotaxonomic aspects are discussed briefly

Dehydro­brachylaenolide: an eudesmane-type sesquiterpene lactone

The three-ring eudesmanolide, C15H16O3, is a natural product isolated from Dicoma anomala Sond. (Asteraceae). The compound contains an endo–exo cross conjugated methyl­enecyclo­hexenone ring with an envelope conformation trans-fused with cyclo­hexane and trans-annelated with an α-methyl­ene γ-lactone. The absolute structure was assigned by optical rotation measurements compared to those from the synthetic compound with known stereochemistry. The crystal packing is consolidated by C—H⋯O interactions

Thiarubrine A, a bioactive constituent of Aspilia (Asteraceae) consumed by wild chimpanzees

Two African species of Aspilia (Asteraceae), which are used medicinally by man and which are eaten by wild chimpanzees in an unusual manner, were found to contain the potent antibiotic thiarubrine A as a major leaf phytochemical. Its presence in leaf material strengthens the view that the feeding behavior of wild chimpanzees is related to special physiological or pharmacological effects on the animals.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42789/1/18_2005_Article_BF02004537.pd

Processing of Thionin Precursors in Barley Leaves by a Vacuolar Proteinase

Thionins are synthesized as precursors with a signal peptide and a long C-terminal acidic peptide that is post-translationally processed. A fusion protein including the maltose-binding protein from Eschrrichia coli (MalE), thionin DG3 froin barley leaves, and its acidic C-terminal peptide has been used to obtain antibodies that recognize both domains of the precursor. In barley leaf sections. mature thionins accuinulated in the vacuolar content, while the acidic peptide was not detected in any cell fraction. Brefeldin A and inonensin inhibited processing of the precursor but its export from the microsomal fraction was not inhibited. Both purified vacuoles aiid an acid (pH 5.5) extract from leaves processed the fusion protein into a MalE-thionin and an acidic peptide fragment. A 70-kDa proteinase that effected this cleavage was purified froin the acid extract. Processing of the fusion protein by both lysed vacuoles and the purified proteinase was inhibited by Zn2+ and by Cu2+, but not by inhibitors of the previously described vacuolar processing thiol or aspartic proteinases. In vivo processing of the thionin precursor in leaf sections was also inhibited by Zn+, and Cu2+, Variants of the fusion protein with altered processing sites that represented thme of thionin precursors from different taxa were readily processed by the proteinase, whereas changing the polarity of either the C-terminal or N-terminal residues of the processing site prevented cleavage by the proteinase

An Agent-based Collective Model to Simulate Peer Pressure Effect on Energy Consumption

This paper presents a novel model for simulating peer pressure effect on energy awareness and consumption of families. The model is built on two well-established theories of human behaviour to obtain realistic peer effect: the collective behaviour theory and the theory of cognitive dissonance. These theories are implemented in a collective agentbased model that produces fine-grained behaviour and consumption data based on social parameters. The model enables the application of different energy efficiency interventions which aim to obtain more aware occupants and achieve more energy saving. The presented experiments show that the implemented model reflects the human behaviour theories. They also provide examples of how the model can be used as an analytical tool to interpret the effect of energy interventions in the given social parameters and decide the optimal intervention needed in different cases