Antimicrobial activity of bioactive compounds of Haplopappus multifolius and Haplopappus taeda against human pathogenic microorganisms.

BACKGROUND AND OBJECTIVES: Haplopappus multifolius Phil. Ex Reiche and Haplopappus taeda Reiche are medicinal shrubs native to Chile and are popularly known as "Bailahuén". Regularly, this plant is used for liver, digestive and renal affections, as well as colds and the cleaning of infected wounds. The aim of the study was to identify the responsible compounds for the antimicrobial activity of H. multifolius and H. taeda. MATERIALS AND METHODS: Infusions and ethanolic extracts of H. taeda and H. multifolius were analysed by thin-layer chromatography bioautography (TLC-B) to determine the compounds responsible for the antimicrobial activity against Gram-positive and Gram-negative bacterial strains and yeasts of Bailahuén. Finally, the minimum inhibitory concentration (MIC) of pure compounds isolated was determinate. RESULTS: Extract of Bailahuén had activity only against Gram-positive bacterial strains and this activity was associated with aesculetin, 18-acetoxy-cis-cleroda-3,13E-dien-15-oic acid and aromadendrin-7-methyl ether compounds. CONCLUSION: H. multifolius and H. taeda have antibacterial capacity on different species of Gram-positive bacteria pathogenic for humans.

Biomass, resin and essential oil content and their variability in natural populations of the Chilean crude drug “bailahuén” (Haplopappus spp) / Biomasa, contenido de resina y aceite esencial y su variabilidad en poblaciones naturales de las especies de droga cruda chilena “bailahuén” (Haplopappus spp)

Bailahuén (Haplopappus rigidus, Haplopappus baylahuen, Haplopappus multifolius and Haplopappus taeda; Asteraceae) are medicinal shrubs native to the Andes Mountains of Chile widely used to treat hepatic ailments. At present, exploitation of bailahuén is based on wild collections, affecting the abundance of natural populations. Variability of biomass production and concentration of active compounds in different wild populations of the four Haplopappus species was studied in order to select the best plant material for cultivation. Resins were extracted with dichloromethane and essential oils by distillation. Biomass production of the populations was highest for H. baylahuen and H. rigidus compared with the other species, reaching between 0.56 and 1.61 kg and 1.11-1.48 kg per plant, respectively. No differences were found among populations of the same species. In some H. rigidus populations, the resin content was about a third of the dry weight, whereas plants of H. multifolius had mean values of about 8 percent. In H. baylahuen (11.3-27.7 percent) the resin content of leaves differed significantly among populations, whereas the essential oil ranged from 0.02-0.38 mL*100g DM-1 in H. baylahuen, 0.03-0.5 mL*100 g DM-1 for H. rigidus, and 0.08-0.35 mL*100 g DM-1 for H. taeda. Resin content in stems differed only among H. baylahuen (6.3-15.5 percent) and H. rigidus (10.7-21.2 percent) populations. No significant differences in essential oil content among species could be detected because of the large amount of variation observed among populations. The variation between plants of the same population may indicate favorable selection potential for future breeding programs.

Bailahuén (Haplopappus rigidus, Haplopappus baylahuen, Haplopappus multifolius y Haplopappus taeda; Asteraceae) son arbustos medicinales de la Cordillera de los Andes Chilena ampliamente usados para tratar malestares hepáticos. Actualmente, la explotación del bailahuén se basa en la recolección silvestre, afectando su abundancia. La variabilidad en diferentes poblaciones silvestres de las cuatro especies de Haplopappus fue usada en orden a determinar la potencialidad para seleccionar el mejor material vegetal para cultivo en producción de biomasa y contenido de principios activos. La resina se extrajo por inmersión en diclorometano y el aceite esencial por destilación. Los mayores rendimientos de biomasa se observaron en H. rigidus y H. baylahuen, con valores poblacionales que fluctuaron entre 1,11-1,48 y 0,56-1,61 kg planta-1, respectivamente, sin presentar diferencias entre poblaciones de la misma especie. El contenido de resinas alcanzó en algunas poblaciones de H. rigidus hasta un tercio del peso seco, mientras que en H. multifolius fue de aproximadamente 8 por ciento. En hojas, sólo se observaron diferencias significativas en el contenido de resinas entre poblaciones de H. baylahuen (11,3-27,7 por ciento). El contenido de aceites esenciales en hojas permitió diferenciar poblaciones de H. baylahuen (0,02-0,38 mL*100g MS-1), H. rigidus (0,03-0,50 mL*100g MS-1) y H. taeda (0,08-0,35 mL*100g MS-1). En tallos, el contenido de resina difirió significativamente entre poblaciones de H. baylahuen (6,3-15,6 por ciento) y H. rigidus (10,7-21,2 por ciento). La alta variación del contenido de aceite esencial entre poblaciones no permitió establecer diferencias entre especies. La variación entre poblaciones de la misma especie sugiere un buen pronóstico para futuras selecciones y mejoramiento genético.