Estudo fitoquímico da fração dicloromêtanica dos galhos da Zanthoxylum rigidum (Rutaceae) e atividade Oomiceticida do Pythium insidiosum

Abstract

Brazil is one of the countries with the greatest diversity in its flora and fungi, with potential for studies of new pharmaceutical products of natural origin.Currently, the search for drugs with fewer side effects is growing.Therefore, research into natural products for therapeutic purposes is one of the best alternatives.In Brazil, the species Zanthoxylum rigidum is popularly known as “mamica-da-porca” and “maminha-da-porca”, found mainly in the states of Mato Grosso and Mato Grosso do Sul.The species presents chemical constituents, such as lignans, flavonoids, alkaloids and others.It presents pharmacological activities, including neuroprotective, anticancer, anti-inflammatory, antiviral and antioxidant. The crude hydromethanolic extract of the twigs of Z. rigidum (EBHMZ) MeOH/H2O (8:2) and the liquid-liquid partition that generated the study fraction (dichloromethane) were obtained from previous studies.From this, two substances were isolated, the first being the glycoside 3-O-β-glucopyranosylsistosterol and the polyphenylketone (E)-1,5-bis(4- hydroxyphenyl)pent-1-en-3-one (artamenone).The latter is being isolated for the first time in the genus, where its 1D and 2D spectra and correlations are discussed to confirm the compound by comparing it with literature data. Pythiosis disease is caused by the Oomycete Pythium insidiosum, which is a pseudofungus that causes diseases in humans and animals. The antifungal activity was tested with the microorganism Pythium insidiosum in the hydromethanolic (ZrM), dichloromethane (ZrD), ethyl acetate (ZrA) fractions and in the crude extract (EBHMZ). The 100% MIC for EBHMZ and ZrA demonstrated inhibition at a concentration of 1000µg/mL, the ZrD fraction in the concentration range of 15.6µg/mL and 62.5µg/mL, while ZrM was inactive at the concentrations studied.In the EBHMZ, ZrA and ZrM fractions did not present the Minimum Oomycidal Concentration (MOC) at the concentrations studied, while in the ZrD fraction it exhibited in the range of 15.6 µg/mL and 250 µg/mL.