Antimicrobial activity of Larrea divaricata alkaloids agains olive tree pathogens

BOITEUX JOANA; MONÁRDEZ CAROLINA; FERNÁNDEZ MARÍA DE LOS ANGELES; ESPINO MAGDALENA BELEN; LUCERO GABRIELA; SILVA MARIA FERNANDA

Morelia, Michoacan

Simposio; 23rd Latin-American Symposium on Biotechnology, Biomedical, Biopharmaceutical, and Industrial Applications of Capillary Electrophoresis and Microchip Technology; 2017

Larrea divaricata Cav. (Zygophyllacea) is a perennial woody shrub with a wide distribution inArgentina. In folk medicine, different L. divaricata preparations have been used as antiinflammatory,antirheumatic, dysphoretic, amenagogic and antimicrobial agents.Phytochemical studies have reported the presence of phenolic compounds, such as flavonoids,simple phenols and phenolic acids. In particular, the alkaloids remain undescribed. Alkaloidsare versatile heterocyclic nitrogen compounds with reported antimicrobial activity againstfungal and bacterial phytopathogens. In this work the alkaloids present in L. divaricata extractwere determined by HPLC-MWD and their antimicrobial activity was evaluated againstPhytophthorapalmivora, P. nicotianae and P. citrophthora. The compounds studied werepiperine, theophylline, theobromine, harmaline, caffeine and nicotine. The extraction ofalkaloids was performed by a miniaturized solid phase extraction using a homemademinicolumn packed with suitable filtering material (C18, 50 mg).Antimicrobial activity of the extract and their alkaloids were assessed using the agar diffusionmethod against P. palmivora, P. nicotianae and P. citrophthora. Among the alkaloidsevaluated, piperine was detected in L. divaricata extract. Antimicrobial activity assaydemonstrated that Phytophthora sp. miceliar growth was inhibited completely by the extract at5 %. On the other hand, piperine at the concentration found in the extract achieved an inhibitionbetween 74-79 % of the pathogens growth. The results reveal that L. divaricata extract has anoutstanding activity against Phytophthora sp. due mainly to the presence of piperine. Thisextract could be considered as a potential alternative to the use of fungicides in the control ofolive tree pathogens.