The genus Aristolochia stands out as the most representative of the Aristolochiaceae plant family, with approximately 550 species distributed around the world, many of which have little or no studies reported in the literature. Investigation of the acetone extract from leaves of Aristolochia warmingii Mast. resulted in the isolation and identification of twenty-three compounds, mostly lignans and neolignans, including the new furofuran lignans warminin A (1), warminin B (2) and warminin C (3). The structures of the compounds were established by comprehensive spectroscopic and spectrometric analyses. A large amount of (–)-epieudesmin (4) was isolated from the extract, which suggests that A. warmingii could be a potential source of this compound. The hexane, acetone, ethanol, and ethanol Soxhlet extracts, in addition to fourteen of the isolated compounds, were evaluated for their ability to inhibit the formation of advanced glycation end products (AGEs), but they did not show significant activities.

GURUPI ISOTHERMS PLOT (GIP): A TOOL WITH INTUITIVE AND FREE GRAPHIC INTERFACE AS AN ALTERNATIVE FOR THE CALCULATION OF ADSORPTION ISOTHERMA PARAMETERS. Gurupi Isotherms Plot (GIP) is a new software and has been developed to facilitate the study of absorptive processes. The adsorption isotherm parameters are determined by the GIP in a non-linearized way, and the current version is implemented to determine the parameters of Langmuir, Freundlich, Dubinin-Radushkevich, coefficient of determination (R2) and average relative error (ARE). In order to facilitate the access and use of the program, a friendly graphical interface has been developed with a response time in seconds. It should also be noted that is a free software. The program was tested with different sets of absorptive data and showed an excellent correlation with the literature data proving its performance.

In this work, we examined how photoluminescence in poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) is affected by morphology, dictated by the mode of preparation. For that, MEH-PPV dilute solutions in good and non-solvents, thick cast films with poly[methylmethacrylate] (PMMA) as inert matrix and spin-coated thin films were prepared. These systems were studied by steady-state and time-dependent fluorescence spectroscopy and electronic microscopy. Unexpected photoluminescent behavior was detected in solutions and films and it was related to different excitons modulated by MEH-PPV conformation. By semi empirical calculations we obtained the singlet and triplet state energies of an MEH-PPV model system and, from time-resolved fluorescence spectroscopy, the existence of short-lived excited states was revealed, enabling us to infer on possible singlet fission in MEH-PPV-based systems.