Abstract The present study was aimed to characterize the chemical profile and evaluate the cytotoxicity and sub-chronic toxicity of the hydroethanolic extract of the xylopodium Mandevilla velame (A.St.-Hil.) Pichon, Apocynaceae. Chemical profile was analyzed by high performance liquid chromatography. Cytotoxic potential of hydroethanolic extract of the xylopodium M. velame was evaluated using Chinese hamster ovary cells. The sub-chronic assessment was done on rats with hydroethanolic extract of the xylopodium M. velame (50, 200 and 800 mg/kg) was orally administered daily for 30 consecutive days. High performance liquid chromatography analysis confirmed the presence of gallic acid, ellagic acid, catechin, epigallocatechin gallate, naringin, myricetin, quercetin and naringenin. hydroethanolic extract of the xylopodium M. velame tested concentrations did not alter the viability of Chinese hamster ovary cells. In the sub-chronic test, 50 and 200 mg/kg were safe, but there were significant changes in relation to weight gain and water consumption by animals that received 800 mg/kg of hydroethanolic extract of the xylopodium M. velame. Among the haematological and biochemical parameters evaluated, only the number of neutrophils, lymphocytes, and creatinine concentration were changed at 800 mg/kg. Phytochemical profile of hydroethanolic extract of the xylopodium M. velame revealed the presence of phenolics and flavonoid compounds. The in vitro cytotoxicity assay result demonstrated that hydroethanolic extract of the xylopodium M. velame had no cytotoxic effects in Chinese hamster ovary cells. In the in vivo models, hydroethanolic extract of the xylopodium M. velame was shown to be relatively safe after sub-acute administration in rats which is relation to that the population daily takes a total dose of the plant xylopodium decoction or infusion about 23.29 times lower than the no-observed-adverse effect level dose in rats.

RESUMOA composição da própolis depende do tempo, da vegetação e a localização da área de coleta. Este estudo teve como objetivo determinar as características físicas e químicas, o teor de compostos fenólicos e capacidade antioxidante da própolis de abelhas nativas sem ferrão (Meliponinae) e Apisdo Estado do Tocantins. Para a obtenção dos extratos empregou-se extração com etanol 80% (v/v). Os parâmetros analisados foram: perda de peso por dessecação a 105 °C, cinzas, Teor de cera e pH. Além dessas foi mensurada a atividade antioxidante e o teor de compostos fenólicos totais. Adicionalmente os extratos de própolis foram também analisados por cromatografia líquida de alta eficiência. O teor de compostos fenólicos totais variou entre 121,78 e 631,29 (mg GAE g-1). A atividade antioxidante expressa pelo valor de CE50 variou entre 29,81 e 845,38 µg mL-1. As análises por cromatografia líquida de alta eficiência permitiram inferir a existência de compostos fenólicos. Os resultados indicaram que as amostras de própolis estudadas constituem boas fontes de antioxidantes naturais. A variedade de compostos fenólicos identificada neste estudo, e as diversas funções biológicas relatadas na literatura para estes compostos, indicaram que a própolis de abelhas sem ferrão (Meliponinae) e Apistem um grande potencial farmacológico.

ABSTRACTThe composition of propolis depends on time, vegetation and the location of the collection area. The objective of this study was to determine the physicochemical characteristics, the concentration of phenol compounds and the antioxidant capacity of propolis of native stingless bees (Meliponinae)and Apis from the State of Tocantins. Extraction with 80% ethanol (v/v) was performed in order to obtain the extracts. Parameters examined were: propolis mass loss by desiccation at 105 ºC, ashes, wax concentration and pH. Furthermore, the propolis antioxidant activity was measured, as well as the total concentration of phenol compounds. The extracts were also analyzed by high performance liquid chromatography. The total concentration of phenol compounds varied between 121.78 and 631.29 (mg GAE g-1). The antioxidant activity expressed by the value of CE50 varied between 29.81 and 845.38 µg mL-1. High performance liquid chromatography analysis allowed us to infer the existence of phenol compounds. The results indicated that the studied propolis samples constitute good sources of natural antioxidants. The variety of phenol compounds identified in this study, and the diverse biological functions reported in literature for these compounds indicated that this stingless bee propolis (Meliponinae) and Apis has a high pharmacological potential.

The marine diatom Coscinodiscus wailesii has attracted ecological interest because their blooms affect fishing areas. The aim of this work was the isolation, extraction and partial chemical characterization of soluble exopolysaccharide and bound exopolysaccharide from C. wailesii. Cultures were grown in Guillards f/2 medium under controlled conditions of temperature, aeration, photoperiod and light intensity. Percentage of carbohydrate, uronic acids, sulfates groups and cellular lipids was determined. Ion exchange chromatography of exopolysaccharides produced three fractions whose partial chemical structures were disclosed using 13C NMR and methylation techniques.