Two spirosteroid analogues were synthesized and evaluated for their in vitro neuroprotective activities in PC12 cells, against glutamate-induced excitotoxicity and mitochondrial damage in glucose deprivation conditions, as well as their anti-inflammatory potential in LPS/IFNγ-stimulated microglia primary cultures. We also evaluated the in vitro anti-excitotoxic and anti-inflammatory activities of natural and endogenous steroids. Our results show that the plant-derived steroid solasodine decreased PC12 glutamate-induced excitotoxicity, but not the cell death induced by mitochondrial damage and glucose deprivation. Among the two synthetic spirosteroid analogues, only the (25R)-5α-spirostan-3,6-one (S15) protected PC12 against ischemia-related in vitro models and inhibited NO production, as well as the release of IL-1β by stimulated primary microglia. These findings provide further insights into the role of specific modifications of the A and B rings of sapogenins for their neuroprotective potential.

The composition of the repugnatorial secretion of some populations of the Cuban endemic millipede Rhinocricus inhabiting in the western region of the Cuban archipelago has been developed. Several quinonoids metabolites were identified. From some individuals (males), collected in forest and karst regions, 850 μg of a deep brown-red secretion were obtained, and directly introduced into analytical instrumental (GC-MS and FTIR). The analysis of FTIR and GC-MS spectra shows that major components of secretions are substituted hydroquinones, 1,4-benzoquinones and aldehydes. The biological effects of these defensive secretions were evaluated on pathogenic microorganisms, showing interesting antimicrobial action. The ecological and evolutionary significance of chemical differentiation in millipedes populations require further study.

The utilization of used frying oil (AFU) as an eco-sustainable and economic resource constitutes a viable and technically feasible strategy at the meso and macro scale for R&D programs in universities and in the implementation of policies for the use of waste with high added value. The AFU from some gastronomic centers in the city of Esmeraldas was used as raw material to obtain biofuel (biodiesel) via trans-esterification under heterogeneous catalytic conditions. Vanadyl phosphate (VOPO₄) synthesized from depleted divanadium pentoxide from sulfuric acid synthesis was used as a catalyst for the process. To obtain biodiesel, pre-treatment processes were applied to the raw materials to eliminate solids and reduce moisture and acidity indexes; combustion in microwave ovens, calcination and sonochemical synthesis to obtain the catalyst. Using frying oil, vanadyl phosphate and methanol in a micro-reactor, at 115 °C and with 3% catalyst, biodiesel was obtained with satisfactory characteristics and yield. The optimum conditions determined for the trans-esterification process were: oil/methanol molar ratio of 1:12.83 and 4.85 hours of reaction.

Ecuador is one of the countries in the Latin American region with a high textile production. However, chemical treatment strategies in the Ambato, Tungurahua and Quito areas are inefficient and not systematically applied, and the volumes of dyes and pigment-type contaminants generate serious environmental problems. The treatments of indigo textile wastewater and related indigo derivatives are very complex. Taking these into consideration, a simple photochemical protocol in heterogeneous conditions was developed, for degrading “blue-indigo” (Ambato textile group) in solution, using TiO₂ (Degussa P25, with a purity of ≈99% and BET surface area 50 ± 15 m²/g) and solar light at lab scale. The photocatalytic oxidation of “blue-indigo” in aqueous solution was assessed by solar irradiation, in the presence of TiO₂ particles. The effect of indigo concentrations, pH and TiO₂ loading for maximum degree of degradation were evaluated. The mineralization of “blue-indigo” was reported by measuring COD-i and COD-f of the solution that was irradiated with sunlight under optimized conditions. The results enable the re-designing of strategies for controlling contamination in textile wastewaters in eco-sustainable conditions for Ecuador.

The poly-component composition of repugnatorial secretions isolated from Rhinocricus duvernoyi Kasrh 1981 eco-geographical populations, inhabiting in the eastern zone of Cuban archipelago, was analyzed using GC-MS. Were identified several benzoquinonoids and related derivatives, revealing the existence of a singular compositional heterogeneity at a geographical scale. The preliminary molecular-geographic mapping of the Cuban archipelago detailed the presence of 3 chemotypes in the east region. The work reports a structural-chromatographic molecular database containing the components of defensive secretions.

The relationship between properties of aromatic polyamides and the structure and pKa of substituted diamine monomers allows for modeling and designing the synthesis of polymers with special properties for different uses (dialysis membranes, ion exchange systems, to thermo-resistant materials and impact protection devices). Nuclear Magnetic Resonance is a versatile analytical tool for such purposes. Based on the obtained equations (pKa = 13.1512 − 1.67039 × (ppm)), and chemical shift (, ppm) = −7.0593 − (37.57628 × φ) the reactivity of the monomers can be calculated and selectively modify some properties of polyamides. Aromatic diamines were synthetized according to established protocols and statistical-molecular studies were developed using Hyperchem pack-2005 and Mopac-6.