Abstract The aim of this work was to determine the total phenolic content and evaluate the antioxidant, antibacterial, photoprotective and cytotoxic properties of corn silk ethanol extract prepared from corn silk that was air-dried at room temperature. Corn silk ethanol extract has a high content of phenolic compounds. The concentrations of ethanol extract required to produce 50% of maximal effect (EC50) in DPPH and ABTS radical scavenging assays were 489.0 and 166.1 µg/mL respectively, indicating low activity when compared to the positive control. The ethanolic extract of corn silk showed antibacterial activity, mainly on Gram-positive bacteria. The in vitro sun protection factor (SPF) of the ethanolic extract of corn silk incorporated into sunscreen UVA-UVB 5% gel with Pemulen TR-1® was evaluated for the first time. A relative increase in SPF efficacy was observed for the extract when the sunscreen was incorporated. The ethanolic extract of corn silk and the gel were considered non-cytotoxic. The corn silk ethanolic extract was characterized using ultra performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC-QTOF-MS/MS). Eleven compounds including flavonoids, coumaric acid derivatives, terpenoid, hydroxycinnamic acid derivative and quinic acid derivative were suggested based on their accurate mass and MS/MS spectra.

Resumo O rápido desenvolvimento da química de polímeros nos últimos anos tem acompanhado a introdução dos materiais poliméricos no campo da medicina. Polímeros com aplicações médicas podem ser subdivididos em dois grandes grupos: materiais usados em próteses e a produção de polímeros biologicamente ativos. Neste trabalho foram sintetizados copolímeros possuindo cadeia principal de poli (metacrilato de metila) e cadeias enxertadas de polietilenoglicol (COP GRAFT). A partir da síntese do copolímero enxertado inicial foram realizadas modificações em suas cadeias de modo a aumentar a possibilidade de incorporação de um fármaco que será utilizado em sistema de liberação controlada de medicamentos. Os novos compostos foram obtidos através de duas rotas sintéticas e os produtos formados ao final de cada etapa foram purificados e caracterizados. Através da técnica de infravermelho (FITIR) foi possível observar as bandas de absorções características das ligações P-H, P=O e P-O, que foram inseridas na cadeia do COP GRAFT durante a fosforilação, além das bandas de absorções características do copolímero, antes da fosforilação, como C=O e C-O. A caracterização térmica das amostras utilizando termogravimetria (TGA) e calorimetria diferencial de varredura (DSC) mostrou que apenas o copolímero de diisobutila apresentou temperatura de transição endotérmica e comportamentos de degradação compatíveis a de um polímero. Através da técnica de difração de raios X (XRD) foi possível observar uma modificação da cristalinidade das amostras, provavelmente devido a uma variação da conformação das cadeias após a inserção de novos grupos químicos. Nos cromatogramas obtidos pela técnica de cromatografia de permeação em gel (GPC) percebeu-se aumento de massa após a fosforilação com o grupo diisobutila no COPGRAFT. A reação de fosforilação foi eficiente na obtenção do copolímero de diisobutila e as técnicas aplicadas demonstraram que houve a modificação no copolímero enxertado.

Abstract The rapid development in polymer chemistry has, in recent years, led to the introduction of polymeric materials in the field of medicine. Two major groups of polymers are used for medical applications: prosthetic and biologically active materials. We synthesized copolymers with the main chain consisting of poly (methyl methacrylate) and graft chains of poly(ethylene glycol) (COP GRAFT). Changes were made in the graft copolymer chains for a possible incorporation of a drug, such that it may be used for the controlled release of drugs. The synthesis of these new compounds is based on two synthetic routes and FTIR, differential scanning calorimetry (DSC), thermogravimetry (TGA) and X-ray diffraction (XRD) characterized the products formed at the end of each stage. Through FTIR we observed absorption bands characteristic of P-H, P=O and P-O bonds that were inserted into the polymer chain during phosphorylation of the COP GRAFT, beyond the absorption bands characteristic of the copolymer before phosphorylation, such as C=O and C-O. By TGA and DSC we observed that only the diisobutyl copolymer has endothermic transition temperature and degradation behavior consistent with a polymer. XRD results showed a structural and conformational change in crystallinity of modified chains. Molecular weight and polydispersity of COPGRAFT obtained by GPC increased after phosphorylation with diisobutyl group. The phosphorylation reaction was efficient in obtaining diisobutyl copolymer and the applied techniques confirmed the modification of the COPGRAFT chains.

This paper is a review of the history, synthesis and application of organophosphorus compounds, especially of those of pentavalent phosphorus, such as phosphoramidates, phosphorothioates, phosphonates and phosphonic acids with insecticide and anticancer activities. The organophosphorus compounds with agrochemical applications show great structural variety, They include not only insecticides, but also fungicides, herbicides, and others. The large variety of commercially available organophosphorus pesticides is remarkable. Even more interesting is the high efficiency of some organophosphorus compounds as anticancer agents such as cyclophosphamide and its derivatives.