Experimental treatment of cutaneous leishmaniasis with argentilactone isolated from Annona haematantha

From the hexanic extract of roots of #Annona haematantha an alpha,bêta-unsaturated delta-lactone was isolated and identified as argentilactone. This compound exhibited in vitro activity against various strains of #Leishmania ssp. at 10 microg/ml. BALB/c mice infected with #Leishmania amazonensis$ were treated four weeks after infection with argentilactone by oral or subcutaneous routes for 14 days at 25 mg/kg daily. The reference drug, N-methylglucamine antimonate, was administratered by subcutaneous injections at 100 mg/kg for 14 days. In these conditions, argentilactone showed the same efficacy as the reference drug, reducing by 96% the parasite loads in the lesion and by 50% the parasite burden in spleen. (Résumé d'auteur

Acetogenins and other compounds from Rollinia emarginata and their antiprotozoal activities

Bioactivity-directed fractionation of the MeOH extract of the stem barks of #Rollinia emarginata$ resulted in the isolation of six compounds, four acetogenins, rolliniastatin-1, sylvaticin, squamocin, and rollidecin B, one lignan, lirioresinol B, and an oxoaporphine, liriodenin. Their structures were determined by spectroscopic analysis and their in vitro leishmanicidal and trypanocidal properties are reported. (Résumé d'auteur

Surface Structure and Electron Transfer Dynamics of the Self Assembly of Cyanide on Au 111

A vibronic resonance between Au{111} surface states and adsorbed CN vibrations has been predicted, which we target for study. We have formed stable monolayers of cyanide on Au{111} and observe a hexagonal close-packed lattice with a nearest neighbor distance of 3.8 ± 0.5 Å. Cyanide orients normal to the surface attached via a Au–C bond. We show that the substrate–molecule coupling is particularly strong, leading to ultrafast electron transfer from the cyanide molecules to the Au{111} substrate as measured by resonant Auger spectroscopy using the core–hole clock method. The CN/Au{111} system is a simple example of a strongly interacting adsorbate–substrate system and will be the subject of a number of further studies, as discussed