LAPACHOL, β-LAPACHONA E HIDROXI-HIDROLAPACHOL: EXTRAÇÃO, SÍNTESE, CARACTERIZAÇÃO E APLICAÇÃO COMO INIBIDORES DO CRESCIMENTO DE FUNGOS PATOGÊNICOS DA SOJA

Abstract

Lapachol is a natural organic compound derived from naphthoquinone which can be isolated from various plant species, mainly from the heartwood of the purple Ipê and its entire family (Bignoniaceas). Lapachol is one of the most versatile biologically active compounds, which is known due to its anticancer, antiinflammatory, analgesic, antibiotic, antimalarial, antitripanosome, and antiulcerogenic properties. From this compound are synthesized two derivatives, β-Lapachona, which started on cancer activity studies from Lapachol, and hydroxyhydrolapachol, compound synthesized from β-Lapachona itself, whose bioactive properties are still being studied. In this context, the present work presents the extraction of Lapachol from the heartwood of purple Ipê, the synthesis of its derivatives, β-Lapachona and hydroxyhydrolapachol, and the application of lapachol as a growth inhibitor of soybean pathogenic fungi. Lapachol and its derivatives were obtained with yields of about 70%, confirmed by 1H-NMR and 13C-NMR, and its purity validated by HPLC. Lapachol has been investigated as a growth inhibitor of Fusarium sp., Sclerotium rolfsii, Trichoderma sp., Colletotrichum truncatum and Cylindrocladium scoparum, and has shown promising results for all the tested concentrations, presenting inhibition degrees of up to 60%, especially for Sclerotium rolfsii where it presented inhibition of up to 94.5%. However, microbiological assays are still under development for both Lapachol and its derivatives, and the prospect is to find the best experimental conditions for a field application.