This work describes the synthesis, molecular structure, and packaging of the compounds 6-bromo-2,3-dimethoxybenzaldehyde (6-BRB) and 5-bromo-2,3-dimethoxybenzaldehyde (5 BRB). Characterization in the solid-state was carried out by X-ray diffraction, and the analysis of the interactions was described by the Hirshfeld surface, which helps in understanding the effect of replacing the bromine position in the aromatic ring. Both compounds (6-BRB and 5-BRB) crystallized in the space group P21/c and are stabilized with C-HO interactions, but only the 6-BRB has a halogen-type interaction. Theoretical calculations, carried out by the density functional theory at the CAM-B3LYP/6-311++G(d,p) level of theory in gas phase, provided information on their electronic properties. The geometric properties were compared to experimental data, and the analyses of the frontier molecular orbitals and the molecular electrostatic potential (MEP) maps were obtained to predict the physical-chemical properties. The supramolecular arrangements were analyzed throughout complexation interactions and corrected by counterpoise method. Hyperconjugation energies were employed to examine the stability of the intermolecular interactions of the compounds. The interaction intensities were determined through the topological parameters obtained through the quantum theory of atoms in molecules model.

ABSTRACT Low quality barley that has been rejected for the malt production process can be used to produce value added products, particularly enzymes. Hence, in this work the starch was extracted and used to produce amylolytic enzymes by Aureobasidium pullulans. Using 50 g/L of barley raw starch, glucoamylase, α-amylase, α glucosidase and β-glucosidase enzymes were produced with maximum activities of 193, 7.4, 8.1 and 8.5 U/mL, respectively. After 30 h of fermentation a crude extract was obtained, which was used as enzymatic source for the saccharification of starch from three sources at 10 g/L: barley, soluble (from potato) and corn. First, two reaction solvents (water and acetate buffer) and the addition of calcium (Ca2+) were evaluated. Afterwards, starch gelatinization was evaluated and finally experiments varying the starch concentration (from 50 to 400 g/L) were conducted. Using water as solvent and the Ca2+ addition had a positive effect, resulting in a maximum glucose concentration of 3.84, 0.84 and 0.4 g/L from barley, soluble and corn starches, respectively. In the other hand, starch gelatinization was positive for soluble and corn starches, enhancing hydrolysis in 23 and 25 %, respectively. Increasing the starch concentration to 50 g/L was the best condition, enhancing hydrolysis in 3.2, 40 and 42 % from barley, soluble and corn starches, respectively. This work demonstrates that low quality raw barley starch can be used for the production of value added products such as enzymes.

RESUMEN La cebada de baja calidad rechazada para el proceso de producción de malta puede ser utilizada para la obtención de productos de valor agregado, particularmente enzimas. En este trabajo se extrajo almidón de cebada y se usó para producir enzimas amilolíticas por Aureobasidium pullulans. Utilizando 50 g/L de almidón, se produjeron glucoamilasa, α-amilasa, α-glucosidasa y β-glucosidasa con actividades máximas de 193, 7.4, 8.1 y 8.5 U/mL, respectivamente. A las 30 h de fermentación se obtuvo un extracto enzimático crudo que se utilizó para sacarificar almidón de tres fuentes a 10 g/L: cebada, soluble (papa) y maíz. Primero, fueron evaluados dos medios de reacción (agua y solución tampón de acetato) y la adición de calcio (Ca2+). Posteriormente, se evaluó la gelatinización del almidón y finalmente se realizaron experimentos aumentando la concentración de almidón (50 a 400 g/L). El agua y la adición de Ca2+ tuvieron un efecto positivo, resultando una concentración máxima de glucosa de 3.84, 0.84 y 0.4 g/L para almidón de cebada, soluble y de maíz, respectivamente. La gelatinización del almidón fue positiva para el almidón soluble y de maíz, aumentando la hidrólisis en 23 y 25 %, respectivamente. El incremento de la concentración de almidón a 50 g/L fue la mejor condición; aumentó la hidrólisis en 3.2, 40 y 42 % para almidón de cebada, soluble y de maíz, respectivamente. Este trabajo demuestra que el almidón de cebada de baja calidad puede ser aprovechado para la obtención de productos de valor agregado, como las enzimas.