Estudio fitoquímico de liquen Thamnolia vermicularis (Sw.) Ach. ex Schaer) presente en la provincia del Azuay

Abstract

The present work focuses on the study of lichen Thamnolia vermicularis, present in Azuay Province, as a source of antimicrobial and antifungal compounds. Species of lichen under study were collected at Cajas National Park, Tres Cruces. The taxonomic identification was carried out with the support of Blgo. Freddy Nugra (Universidad del Azuay). Previously dried and pulverized lichen biomass was submitted to extraction, by means of Soxhlet method. Solvents of increasing polarity were used for this purpose: hexane, chloroform, ethyl acetate, and methanol. The separation pattern of the extracts obtained in Thin Layer Chromatography was analyzed. The best separation chromatographs were used for bioautography test, aimed to evaluate the antimicrobial potential of the chromatographically separated compounds. To compare the retention factors of the compounds present in the extracts of T. vermicularis with those reported by Culberson et al. for secondary metabolites present in lichens, thin layer chromatography was developed under conditions described in the reference work. The antimicrobial activity tests were carried out towards the bacteria Klebsiella pneumoniae and Pseudomona aeruginosa and the fungi Penicillium crysogenum and Aspergillus fumigatus. The antimicrobial capacity of bioautographs was compared with the agar diffusion assay using organic extracts. A moderate antimicrobial activity of the extracts from T. vermicularis, was displayed, versus the inactivity of the bioautographs. These results suggest the antimicrobial activity may be owed to synergism strategies, since the chromatographic separation leads to the inactivity of the extract.