EXTRATOS DAS FOLHAS DE SANGRA D’ÁGUA (CROTON URUCURANA BAILLON): obtenção, caracterização fitoquímica, nanoencapsulamento e avaliação da atividade antifúngica

Abstract

Plant extracts stand out more and more due to their benefits presented, for example antioxidant activity. Among the sources that can be used to extract active ingredients, there is the Croton urucurana Baillon plant, an Euphorbiaceae, popularly known as bleeding water. Extracts from parts of this plant have several applications, as well as medicine and agriculture. However, they have low bioavailability and rapid degradability, so nanoparticles can be used as an alternative technology because they help to increase bioavailability, controlling the release of the asset and protecting it from degradation. Given this the objective was to prepare extracts of the Croton urucurana Baillon leaves, to evaluate their antioxidant activity, total phenolics and carotenoids; develop an analytical method for the identification and quantification of quercetin-3-O-rutinoside by high performance liquid chromatography (HPLC-DAD); perform an antifungal test with hydroethanolic and hexane extracts against the fungi Rhizopus stolonifer and Sclerotinia sclerotiorum. Finally, preparation of nanoparticles, monitoring colloidal stability by UV-Visible spectroscopy and DLS and zeta Potential measurements. Five extracts/fractions were prepared in search of method that would provide better extraction of quercetin-3-O-rutinoside. The method that showed the best performance was hydroethanolic (ethanol/water), making up a quantity of 34,559 mg.g-1 of this compound in the extract. For the antioxidant activity, it was observed that the extracts prepared with polar solvents favored the extraction process and showed greater antioxidant activity, highlighting the hydroethanolic, methanolic and ethanolic extracts. For total phenolics, the extracts that stood out were methanolic, hydroethanolic and ethanolic. For carotenoids, nonpolar solvents favored the extraction process, with the hexane extract having the highest carotenoids concentration, followed by ethyl acetate, ethanolic, hydroethanolic and methanolic extracts. For the antifungal assay, the hydroethanolic and hexane extract showed the same inhibition performance for the fungus Sclerotinia sclerotiorum with a maximum close to 40%, whereas for the fungus Rhizopus stolonifer, the hexane extract showed a better inhibition performance with a maximum close to 62%. The chromatographic analytical method showed linearity in the studied concentration range. The detection and quantification limits (LD and LQ) were 0.18 and 0.54 µg/mL for quercetin-3-O-rutinoside. For alginate nanoparticles containing quercetin-3-O-rutinoside, it was observed that the samples that remained stable for eight months were QR3 and QR4. Resulting in nanoparticles of sizes 67.53 and 201.6 nm and zeta Potential of -22.9 and -25.3 mV, respectively. The encapsulation efficiency values of quercetin-3-O-rutinoside for the prepared formulations were between 95.08 to 99.12%. A factorial design 23 was made with a central point and the effects of the nanoparticle formulations compounds were evaluated and it was found that the efficiency of quercetin-3-O-rutinoside encapsulation is positively influenced by the increase in the amount of alginate and CTAB/Alginate, and negatively influenced by the increasing amount of Tween.