Comparative study of ovatifolin antioxidant and growth inhibition activities.

A comparative study on the effect of arturin (1), ovatifolin (3), deacetylovatifolin (5), and their 1-acetoxyarturin (2), 8-acetoxyovatifolin (4), 1,10-epoxyovatifolin (6), and 11,13-dihydroovatifolin (7) derivatives, isolated from Podanthus ovatifolius and Podanthus mitiqui, on the seedling growth, germination, and respiration of several monocot and dicot weedy target species was carried out. In addition to the inhibitory activity on the bleaching of crocin induced by alkoxyl radicals, these compounds also displayed scavenging properties toward DPPH in TLC autographic and spectrophotometric assays. The results indicate that ovatifolin (3), deacetylovatifolin (5), epoxyovatifolin (6), dihydroovatifolin (7), and the CH(2)Cl(2) extract interfere with pre-emergence of seedlings at the level of respiration. These compounds appear to have selective effects on the radicle and shoot growth of Physalis ixocarpa and Trifolium pratense. Their allelopathic effects are comparable to those of parthenolide, a know natural growth inhibitor.

In vitro antibacterial activity of Chilean red wines against Helicobacter pylori.

The antibacterial activity of sixteen Chilean red wines (Cabernet Sauvignon, Cabernet Merlot, Cabernet Organic and Pinot Noir), and the active extracts of two randomly selected wines were assayed for their antibacterial activity on six strains of Helicobacter pylori isolated from gastric biopsies. The active fraction of the wines was obtained by dichloromethane extraction, and the antibacterial activity of the wines and extracts was evaluated by an agar diffusion method. All the red wines studied showed some antibacterial activity on the six strains of H. pylori, although the strains were heterogeneous in their susceptibility to each particular wine. The active fraction of the two wines selected also showed good activity against the strains tested. The main active compound was identified as resveratrol. The results presented indicate that Chilean red wines have antibacterial activity against H. pylori, which depends mainly on the presence of resveratrol.

Estudio de susceptibilidad al vino tinto chileno y al resveratrol sobre cepas de helicobacter pylori / Helicobacter pylori strains susceptibility to chilean red wine and resveratrol

En los últimos años se han estudiado numerosas propiedades del vino tinto, algunas relacionadas con la salud humana. Así, se ha observado disminución de enfermedades cardiovasculares e infección por H. pylori en bebedores moderados, propiedad que podría estar condicionada a la presencia de resveratrol en el vino. En este trabajo, se investigó la actividad anti H. pylori de 16 vinos tintos chilenos (cepas Cabernet Sauvignon, Cabernet Merlot, Cabernet Orgánico y Pinot Noir) y de extractos activos de dos vinos seleccionados al azar, utilizando el método de difusión en agar. El 100 por ciento de los vinos tintos en estudio presentó algún grado de actividad antibacteriana sobre las seis cepas de H. pylori estudiadas. Por otra parte, las cepas fueron heterogéneas en su susceptibilidad frente a un mismo vino. El extracto activo (extracto diclorometánico) de los dos vinos seleccionados al azar demostró buena actividad sobre todas las cepas ensayadas, y el compuesto activo principal resultó ser el resveratrol. Sólo una de las seis cepas fue moderadamente resistente a 80 µg/ml del compuesto puro, obtenido comercialmente. Los resultados presentados indican que los vinos tintos chilenos tienen actividad antibacteriana sobre H. pylori, la cual depende principalmente de la presencia de resveratrol

Screening of Chilean plants for anticancer activity. I.

Extracts prepared from 519 samples of plant material were evaluated for anticancer activity against the usual systems. The results of the antitumor testing showed that 156 of these extracts gave initial indications of anticancer activity in one or more tumor systems. The activity was confirmed in 14 samples.