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the 1st Portuguese-Brazilian Organic Chemistry Symposium.
Abstract
N-phenylquinazolin-4-amines derivatives were obtained in high
yields with excellent purity from the reaction of 2-aminobenzamide, orthoesters, and
substituted anilines in the presence of Silica-Supported Preyssler Nanoparticles and variuos
heteropolyacids (HPAs).
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Pomegranate (Punica granatum) bioactive compounds (polyphenols and anthocyanins) of juice (PJ) and ethanolic extracts (PE) were encapsulated with maltodextrin (MD) or soybean protein isolates (SPI) by spray drying using a 22 statistical factorial design for each systems studied (PJ–MD, PJ–SPI, PE–MD and PE–SPI) considering the proportion of coating material and the inlet temperature as independent variables. The stability of the bioactive compounds microcapsules powders obtained under optimal conditions for each system was studied at 60 °C in oven for 56 days. The polyphenols encapsulating efficiency was significantly better in SPI matrix whereas for anthocyanins was in MD matrix. By the other hand, during the storage, the MD microcapsules provided a significant greater protective effect on the polyphenols and anthocyanins than SPI, as was shown by the lower degradation rate constants. When the microcapsules were added to yogurt the stability of the bioactive compounds followed a similar behaviour to those without encapsulation, except for PE–MD.
Anthocyanin stability and antioxidant activity of powdered açai juice was evaluated throughout 120 days. Powders were produced by spray drying using four types of carrier agents: maltodextrin 10DE, maltodextrin 20DE, gum Arabic and tapioca starch. Samples were stored at different temperatures (25 and 35 °C) and water activities (0.328 and 0.529), in order to verify the effect of these conditions on anthocyanin degradation and antioxidant activity reduction. Anthocyanin degradation exhibited two first-order kinetics: the first one, with higher reaction rate constant, up to 45–60 days of storage, and the second one, after this period, with lower degradation rate. Both temperature and water activity negatively affected anthocyanin stability. Antioxidant activity also decreased with increasing water activity, but was higher for the powders stored at 35 °C. Maltodextrin 10DE was the carrier agent that showed the best pigment protection and the highest antioxidant activity, for all the conditions studied.
This review is an updated and expanded version of the three prior reviews that were published in this journal in 1997, 2003, and 2007. In the case of all approved therapeutic agents, the time frame has been extended to cover the 30 years from January 1, 1981, to December 31, 2010, for all diseases worldwide, and from 1950 (earliest so far identified) to December 2010 for all approved antitumor drugs worldwide. We have continued to utilize our secondary subdivision of a "natural product mimic" or "NM" to join the original primary divisions and have added a new designation, "natural product botanical" or "NB", to cover those botanical "defined mixtures" that have now been recognized as drug entities by the FDA and similar organizations. From the data presented, the utility of natural products as sources of novel structures, but not necessarily the final drug entity, is still alive and well. Thus, in the area of cancer, over the time frame from around the 1940s to date, of the 175 small molecules, 131, or 74.8%, are other than "S" (synthetic), with 85, or 48.6%, actually being either natural products or directly derived therefrom. In other areas, the influence of natural product structures is quite marked, with, as expected from prior information, the anti-infective area being dependent on natural products and their structures. Although combinatorial chemistry techniques have succeeded as methods of optimizing structures and have been used very successfully in the optimization of many recently approved agents, we are able to identify only one de novo combinatorial compound approved as a drug in this 30-year time frame. We wish to draw the attention of readers to the rapidly evolving recognition that a significant number of natural product drugs/leads are actually produced by microbes and/or microbial interactions with the "host from whence it was isolated", and therefore we consider that this area of natural product research should be expanded significantly.