ABSTRACT
The techniques used to monitor the quality of the biodiesel are intensely discussed in the literature, partly because of the different oil sources and their intrinsic physicochemical characteristics. This study aimed to monitor the thermal degradation of the fatty acid methyl esters of Sesamum indicum L. and Raphanus sativus L. biodiesels (SILB and RSLB, resp.). The results showed that both biodiesels present a high content of unsaturated fatty acids, â¼84% (SILB) and â¼90% (RSLB). The SILB had a high content of polyunsaturated linoleic fatty acid (18 : 2), about 49%, and the oleic monounsaturated (18 : 1), â¼34%. On the other hand, RSLB presented a considerable content of linolenic fatty acid (18 : 3), â¼11%. The biodiesel samples were thermal degraded at 110°C for 48 hours, and acid value, UV absorption, and fluorescence spectroscopy analysis were carried out. The results revealed that both absorption and fluorescence presented a correlation with acid value as a function of degradation time by monitoring absorptions at 232 and 270 nm as well as the emission at 424 nm. Although the obtained correlation is not completely linear, a direct correlation was observed in both cases, revealing that both properties can be potentially used for monitoring the biodiesel degradation.
ABSTRACT
Acrocomia aculeata, popularly known as "bocaiúva", is a species used for nutritional purposes and for the treatment of various diseases, as it has, among other things, high levels of antioxidant compounds. This study aimed to assess the toxicological profile of A. aculeata, through acute and subacute toxicity tests. Male and female rats (Wistar) received by gavage 2000 mg/kg of oil extracted from the pulp of A. aculeata (OPAC) for the acute toxicity test and 125, 250, 500 or 1000 mg/kg of OPAC for subacute toxicity test. In the acute toxicity study no mortality or behavioral changes were observed in rats treated with 2000 mg/kg, indicating that the LD50 is higher than this dose. In the subacute toxicity test, the tested doses produced no significant changes in hematological, biochemical or histopathological parameters in the animals exposed. These results demonstrate the absence of acute and subacute toxicity after oral exposure to A. aculeata oil in rats. However, further studies in animals and in humans are needed in order to have sufficient safety evidence for its use in humans.
Subject(s)
Arecaceae/chemistry , Plant Oils/toxicity , Animals , Blood Cell Count , Fatty Acids, Monounsaturated/analysis , Female , Lethal Dose 50 , Male , Organ Size/drug effects , Plant Oils/chemistry , Rats , Rats, Wistar , Sex CharacteristicsABSTRACT
Para obter novos compostos com atividade antibacteriana, foram preparados os derivados 2,4-diidróxi-6-metilbenzoatos (orselinatos) e o ácido 2,4-diidróxi-6-metilbenzóico (ácido orselínico) através de reacões de alcoólise do ácido lecanórico. Todas as substâncias foram testadas contra bactérias Gram-positivas e Gram-negativas pelo método da microdiluicão. Staphylococcus aureus, Xanthomonas campestris var. vesicatoria and Ralstonia solanacearum foram mais sensíveis ao 2,4-diidróxi-6-metilbenzoato de n-propila, 2,4-diidróxi-6-metilbenzoato de n-pentila e 2,4-diidróxi-6-metilbenzoato de n-hexila com valores de CIM (Concentracão Inibitória Mínima) variando de 62,5 a 7,8 µg.mL1. Esses resultados mostraram que a homologacão da cadeia carbônica pode conduzir a compostos mais ativos.
