Preliminary phytochemical characterization of Heliotropium curassavicum and H. veronicifolium from Tucumán with pharmacological interest in goat farming

In Argentina, goat farming represents an important livestock activity, being Tucumán a province with productive areas represented by Trancas, Tafí del Valle and Graneros departments. Among biotic diseases that affect this activity, infectious diarrhoea stands out caused by Escherichia coli. Emergent bacterial resistance to antibiotics mainly used in livestock production affects their profitability and leads researchers to consider alternative therapies based on metabolites from plants. Boraginaceae plant family produces a large amount of secondary metabolites, such as alkaloids, and phenolic compounds with well-known antibacterial properties, standing out Heliotropium genus. In our laboratory, preliminary studies on extracts of three species of Heliotropium from Tucumán demonstrated antimicrobial activity against bacteria related to infectious diarrhea in goats and food-borne pathogen. In this work, chemical composition of H. curassavicum (from Tapia and Santa Maria areas) and H. veronicifolium (from Tapia area) extracts, was determined with the aim of characterizing them and inferring presence of compounds families with antimicrobial potential. The extractions were carried out with ethyl ether, isopropanol-water and methylene chloride. After a comparative analysis considering plant species and collection area, some variations were found. Polar compounds showed the highest yields and FT-IR reveal similar functional group profiles in all extracts related to phenols, tannins, flavonoids, triterpenes, steroids, and alkaloids. The results obtained will allow a further deeper study of antimicrobial activity of fractions enriched in phenolic compounds and alkaloids in accordance with the extensive bibliographic evidence supporting their biological activities.