Estudo fitoquímico de Chrysophyllum gonocarpum (Mart. & Eichler ex Miq.) Engl. (Sapotaceae) com vistas ao desenvolvimento de novos antifúngicos

Abstract

To contribute to the development of new methods for reducing the contamination of coffee beans with Aspergillus ochraceus and ochratoxin A, which is a toxin produced by this fungus, the selection of plants able to produce substances active against such microorganism was aimed in a previously performed study. To continue this study, the present work aimed to isolate and identify the substances in the methanol extract of barks from Crysophyllum gonocarpum, which was one of the selected plants. Initially, the dry form of this extract was subjected to washes with solvents, resulting in three fractions: soluble in hexane, soluble in ethyl acetate and soluble in methanol. Since the last fraction was the most active and presented the greatest mass, it underwent several subsequent fractionations by column chromatography and by high performance liquid chromatography, which resulted in the purification of eleven substances. After analyses by nuclear magnetic resonance, the following structures were attributed to these compounds: (7S*,8S*)-threo-1-C-syringylglycerol 4-O-β-D-glucopyranoside, (7R*,8R*)-threo-1-C-syringylglycerol 4-O-β-D-glucopyranoside, 4-O-β-D-glucopyranosil-3,3´,4´-di-O-methylellagic acid, 4-O-β-D-xylopyranosil-3,3´-di-O-methylellagic acid, (+)-(2R,3R,4S)-lyoniresinol 3α-O-β-D-glucopyranoside, (2R*,3R*,4S*)-lyoniresinol 2α-O-α-L-fucopyranoside-3α-O-β-D-glucopyranoside (unpublished), cuchiloside, kelampayoside A, benzyl-β-primeveroside, 3,4,5-trimethoxyphenol and (7´R*,8S*,8´S*)-5,5´-dimethoxylariciresinol 4´-O-β-D-glucopyranoside. Further studies should be conducted to ascertain the effects these substances have on A. ochraceus.