Withanolides and related steroids

Since the isolation of the first withanolides in the mid-1960s, over 600 new members of this group of compounds have been described, with most from genera of the plant family Solanaceae. The basic structure of withaferin A, a C28 ergostane with a modified side chain forming a δ-lactone between carbons 22 and 26, was considered for many years the basic template for the withanolides. Nowadays, a considerable number of related structures are also considered part of the withanolide class; among them are those containing γ-lactones in the side chain that have come to be at least as common as the δ-lactones. The reduced versions (γ and δ-lactols) are also known. Further structural variations include modified skeletons (including C27 compounds), aromatic rings and additional rings, which may coexist in a single plant species. Seasonal and geographical variations have also been described in the concentration levels and types of withanolides that may occur, especially in the Jaborosa and Salpichroa genera, and biogenetic relationships among those withanolides may be inferred from the structural variations detected. Withania is the parent genus of the withanolides and a special section is devoted to the new structures isolated from species in this genus. Following this, all other new structures are grouped by structural types. Many withanolides have shown a variety of interesting biological activities ranging from antitumor, cytotoxic and potential cancer chemopreventive effects, to feeding deterrence for several insects as well as selective phytotoxicity towards monocotyledoneous and dicotyledoneous species. Trypanocidal, leishmanicidal, antibacterial, and antifungal activities have also been reported. A comprehensive description of the different activities and their significance has been included in this chapter. The final section is devoted to chemotaxonomic implications of withanolide distribution within the Solanaceae. Overall, this chapter covers the advances in the chemistry and biology of withanolides over the last 16 years.Fil: Misico, Rosana Isabel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad de Microanálisis y Métodos Físicos Aplicados a la Química Orgánica (i); ArgentinaFil: Nicotra, V.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; ArgentinaFil: Oberti, Juan Carlos María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Química Orgánica; ArgentinaFil: Barboza, Gloria Estela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Departamento de Farmacia; ArgentinaFil: Gil, Roberto Ricardo. University Of Carnegie Mellon; Estados UnidosFil: Burton, Gerardo. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Orgánica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad de Microanálisis y Métodos Físicos Aplicados a la Química Orgánica (i); Argentin

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Not AvailableThe functional properties of 4 binders, namely corn starch, wheat semolina, wheat flour, and tapioca starches, were evaluated to improve the quality of buffalo meat nuggets processed in retort pouches at F0 12.13. Incorporation of corn starch in buffalo meat nuggets produced more stable emulsion than other binders used. Product yield, drip loss, and pH did not vary significantly between the products with different binders. Shear force value was significantly higher for product with corn starch (0.42 ± 0.0 Kg/cm3) followed by refined wheat flour (0.36 ± 0.010 Kg/cm3), tapioca starch (0.32 ± 0.010 Kg/cm3), and wheat semolina (0.32 ± 0.010 Kg/cm3). Type of binder used had no significant effect on frying loss, moisture, and protein content of the product. However, fat content was higher in products with corn starch when compared to products with other binders. Texture profile indicated that products made with corn starch (22.17 ± 2.55 N) and refined wheat flour (21.50 ± 0.75 N) contributed firmer texture to the product. Corn starch contributed greater chewiness (83.8 ± 12.51) to the products resulting in higher sensory scores for texture and overall acceptability. Products containing corn starch showed higher sensory scores for all attributes in comparison to products with other binders. Panelists preferred products containing different binders in the order of corn starch (7.23 ± 0.09) > refined wheat flour (6.48 ± 0.13) > tapioca starch (6.45 ± 0.14) > wheat semolina (6.35 ± 0.13) based on sensory scores. Histological studies indicated that products with corn starch showed dense protein matrix, uniform fat globules, and less number of vacuoles when compared to products made with other binders. The results indicated that corn flour is the better cereal binder for developing buffalo meat nuggets when compared to all other binders based on physico‐chemical and sensory attributes.Not Availabl

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Not AvailableOur objective was to determine the combined effects of lactate, LDH, and NAD on metmyoglobin reduction in mitochondria isolated from bovine cardiac muscle. Mitochondria were reacted with various combinations of lactate, LDH, NAD, and mitochondrial inhibitors, and oxygen consumption was measured using a Clark oxygen electrode. Mitochondria (3 mg/mL) and bovine metmyoglobin (0.15 mM) also were reacted with substrates/enzymes/inhibitors to determine mitochondria-mediated metmyoglobin reduction in vitro. Combining lactate-LDH-NAD with isolated mitochondria increased oxygen consumption as well as metmyoglobin reduction compared with those of either control mitochondria (without lactate) or mitochondria with added lactate, at pH 5.6 and 7.4 (p < 0.05). The addition of mitochondrial and LDH inhibitors to lactate-LDH-NAD decreased oxygen consumption and metmyoglobin reduction (p < 0.05). NADH formed from lactate-LDH-NAD can be used for nonenzymatic (via the electron transport chain) and enzymatic (NADH-dependent metmyoglobin reductase) metmyoglobinNot Availabl