Bioautography and antifusaric activity of three tar extracts from the pyrolysis of three plants growing wild in the south-west of Algeria

Abstract

Vegetable tars are newly formed resinous products extracted by pyrolysis from wood or bark. Since prehistoric times, they have been used for their adhesive, water-repellent, repellent and finally medicinal properties. This work investigated the use of these vegetable tars as sources of bio-fungicides. The physicochemical properties of the tars obtained in the labor-atories showed a significant yield of 1.22%, 0.66% and 0.51% respectively for the wood of (Jeniperus phoenicea, Olea europeae sylvestris and Acacia torti-lis Sub raddiana). They also showed a density value of 1.22 and a refractive index of about 1.5115 for J.phoenicea, an acid number of 0.39 and a dry matter ratio of 19.86% for A. tortilis Sub raddiana. Considerable antifungal activity of the acetate of three tars against certain fungal phytopathogens (Fusarium) was observed with the most remarkable MIC values ranging from 0.1 mg / ml to 0.46 mg / ml. The J. phoenicea extracts were more active against F. oxysporum f sp albedinis (FOA) strains. The growth of F. solani was more sensitive to acetate extracts from O. europeae. Dichloromethane ex-tracts of A. tortilis Sub raddiana yielded with an average MIC of 0.16 and 1.02 mg / ml, respectively for strains of F. oxysporum and F. graminearum. The bioautography test revealed the presence of 3 antifusaric molecules of interest. These MIC results further merit in vivo tests for the development of future biofungicides.