Evaluación fotoquímica y microbiológica de extractos de Carya illinoensis y Juglans mollis y su incorporación en nanopartículas poliméricas para su potencial aplicación como agente antituberculoso

Tesis (Doctor en Ciencias con Acentuación en Química de Productos Naturales) UANL, 2012.UANLhttp://www.uanl.mx

Contenido fenólico y acción antioxidante de extractos de acículas de Pinus cooperi, P. durangensis, P. engelmanii y P. teocote

Coniferous trees are a vast resource in Durango, Mexico forests and a potential nontimber source of these chemicals, thus, our study for analyzing phenolic content and biological activity in needle extracts from Pinus cooperi (COO), P. durangensis (DUR), P. engelmanii (ENG) and P. teocote (TEO). Pine needles were dewaxed with hexane and extracted with aqueous acetone and methanol. DUR and ENG extracts showed the higher yields, while acetone TEO and methanol ENG extracts showed the highest catechin equivalent (CE) contents. A partial chromatographic purification on acetone TEO extracts produced five fractions, the third one (F3-TEO) had the highest phenolic content (489,6 CE). In condensed tannins contents, acetone and methanol TEO extracts, as well fraction F3-TEO were the best (24,3, 15.7 and 44,4 mg/g extract, respectively). In DPPH activity, the more effective CE50 were obtained from TEO acetone extract (223,5 ppm) and fractions F3-TEO (145,0 ppm) and F4-TEO (150,8 ppm). In ABTS assay, TEO acetone (27,7%) and methanolic (18,2%) extracts, and fractions F3-TEO (60,1%) and F4-TEO (55,8%) were the best. In LDL assay the highest inhibitory activity was shown by acetone extracts, particularly ENG (99,4%) at 90 ppm. Therefore acetone extracts from TEO and ENG may have utilization as a potential source of bioactive phenolics.Durango es uno de los estados con mayor riqueza forestal, siendo el pino el género dominante en sus bosques, de ahí el interés por evaluar química y biológicamente extractos de acículas de Pinus cooperi (COO), P. durangensis (DUR), P. engelmanii (ENG) y P. teocote (TEO). Se practicaron extracciones sucesivas con acetona y metanol acuosos de acículas de pino desengrasadas previamente con hexano, en las cuales DUR y ENG mostraron respectivamente los mejores rendimientos. Los valores más altos del contenido de fenoles totales fueron los extraíbles acetónicos de TEO y los metanólicos de ENG. Se realizó una purificación cromatográfica a los extraíbles acetónicos de TEO, generando cinco fracciones; F3-TEO con 489,6 EC presentó el mayor contenido fenólico. Los extractos acetónicos y metanólicos de TEO y la fracción purificada F3-TEO presentaron la mayor concentración de taninos condensados. En el ensayo de DPPH, los extractos más relevantes según su concentración efectiva media (CE50) fueron los acetónicos de TEO (223,5 ppm) y las fracciones F3-TEO (145,0 ppm) y F4-TEO (150,8 ppm). De manera similar, en el ensayo de ABTS, los extractos de TEO en acetona (27,7%) y en metanol (18,2%), así como las fracciones F3-TEO (60,1%) y F4-TEO (55,8%) mostraron la supresión más elevada de la oxidación. En el ensayo de la oxidación de LDL, la mayor actividad inhibitoria fue mostrada por extractos acetónicos, particularmente por ENG (99,4%) a una concentración de 90 ppm. Los extractos acetónicos de TEO y de ENG presentan potencial como fuente de polifenoles bioactivos

High-Intensity Ultrasound Processing Enhances the Bioactive Compounds, Antioxidant Capacity and Microbiological Quality of Melon (Cucumis melo) Juice

The bioactive compounds, antioxidant capacity and microbiological quality of melon juice processed by high-intensity ultrasound (HIUS) were studied. Melon juice was processed at two ultrasound intensities (27 and 52 W/cm2) for two different processing times (10 and 30 min) using two duty cycles (30 and 75%). Unprocessed juice was taken as a control. Total carotenoids and total phenolic compounds (TPC) were the bioactive compounds analyzed while the antioxidant capacity was determined by DPPH, ABTS and FRAP assays. The microbiological quality was tested by counting the aerobic and coliforms count as well as molds and yeasts. Total carotenoids increased by up to 42% while TPC decreased by 33% as a consequence of HIUS processing regarding control juice (carotenoids: 23 μg/g, TPC: 1.1 mg GAE/g), gallic acid and syringic acid being the only phenolic compounds identified. The antioxidant capacity of melon juice was enhanced by HIUS, achieving values of 45% and 20% of DPPH and ABTS inhibition, respectively, while >120 mg TE/100 g was determined by FRAP assay. Further, the microbial load of melon juice was significantly reduced by HIUS processing, coliforms and molds being the most sensitive. Thus, the HIUS could be an excellent alternative supportive the deep-processing of melon products