In this research, a new depside of the lichen Everniopsis trulla has been isolated. The extraction was carried out to 400 g of dry sample and ground with ethanol for 3 repetitions, then, it was fractionated by applying column chromatography with the CHCl3-MeOH system and purified by recrystallization with MeOH-Acetone (1: 1); Finally, white crystals in the form of needles (solid C) with a melting point of 198 ° C were obtained, whose structure was elucidated based on spectroscopic data (UV-Visible, IR, NMR-H1, NMR-C13, mass spectrometry and single crystal X-ray diffraction). According to the Science Finder databases, it is a new depside, called trullarin, and it is observed that molecular packing is influenced by both intramolecular and intermolecular forces. Intermolecular hydrogen bonds of O - H -O type binds neighboring molecules forming dimers.

The research study consisted of three stages: firstly, obtaining and characterizing the chitosan extracted from the squid plume, secondly selecting the appropriate variety of custard apple based on the yield of the fruit, and thirdly, studying the synergistic effect between chitosan and citric acid on control of enzymatic browning of custard apple pulp. In the characterization of the chitosan a value of 846 kDa of molecular weight and 78.2% of the degree of deacetylation was obtained. Using a Completely Randomized Design (CRD), three cherimoya varieties (Lisa, Impresa and Umbonata) were evaluated, selecting the Lisa variety for the highest pulp yield; then a Completely Randomized Block Design (CRBD) was used evaluating fourtreatments (T) in triplicate in the standardized pulp, the fourth treatment (0.75% chitosan + 3% citric acid) presented the lowest polyphenoloxidase activity (70,80 PP...