Abstract Averrhoa carambola L. presents in its composition diversity of nutrients and vitamins. The present study aimed to extract water and fat-soluble compounds from this fruit at different stages of maturation (green and mature), perform the physical-chemical characterization as well as evaluate its cytotoxicity against hepatoma cells of Rattus norvegicus (HTC). The physicochemical results showed that the pH and molar acidity is influenced by the fruit maturation state. The fruit presented high percentage of moisture, while the percentage of total minerals (ash) increased according to its maturation stage. The results of the phytochemical screening showed that star fruits present phenolic compounds. The antioxidant activity showed greater potential for the ethanolic extracts of the green and mature star fruit. For HTC cells treated with ethanolic extract of green and mature star fruit the data show absence of cytotoxic effect. The tests with the aqueous extract showed cytotoxic/antiproliferative effect of green and mature star fruit extract, in 24, 48 and 72 hours. The presence of nutraceutical compounds and the cytotoxic/antiproliferative activity were more expressive in the aqueous extract, being an option of easily accessible solvent economic and not harmful to organisms.

Resumo A Averrhoa carambola L. apresenta em sua composição diversidade de nutrientes e vitaminas. O presente estudo teve como objetivo extrair compostos hidrossolúveis e lipossolúveis deste fruto em diferentes estádios de maturação (verde e maduro), realizar a caracterização físico-química, bem como avaliar sua citotoxicidade contra células de hepatoma de Rattus norvegicus (HTC). Os resultados físico-químicos mostraram que o pH e a acidez molar são influenciados pelo estado de maturação dos frutos. O fruto apresentou alto percentual de umidade, enquanto o percentual de minerais totais (cinzas) aumentou de acordo com seu estádio de maturação. Os resultados da triagem fitoquímica mostraram que as carambolas apresentam compostos fenólicos. A atividade antioxidante apresentou maior potencial para os extratos etanólicos da carambola verde e madura. Para células HTC tratadas com extrato etanólico de carambola verde e madura os dados mostram ausência de efeito citotóxico. Os testes com o extrato aquoso mostraram efeito citotóxico/antiproliferativo do extrato de carambola verde e madura, em 24, 48 e 72 horas. A presença de compostos nutracêuticos e a atividade citotóxica/antiproliferativa foram mais expressivas no extrato aquoso, sendo uma opção de solvente de fácil acesso econômico e não prejudicial aos organismos.

This work describes the use of clavulanic acid (CA) precipitation as the final step in the process of purification of CA from fermentation broth as an alternative to conventional methods employed traditionally. The purpose of this study was to use a stable intermediate (t-octylamine) between the conversion of CA to its salt form (potassium clavulanate), thereby enabling the resulting intermediate (amine salt of clavulanic acid) to improve the purification process and maintain the stability of the resulting potassium clavulanate. To this end, response surface methodology was employed to optimize the precipitation step. For the first reaction, five temperatures (6.6 to 23.4 ºC), concentrations of clavulanic acid in organic solvent (6.6 to 23.4 mg/mL) and t-octylamine inflow rates (0.33 to 1.17 drop/min) were selected based on a central composite rotatable design (CCRD). For the second reaction, five temperatures (11.6 to 28.4 ºC), concentrations of clavulanic acid amine salt in organic solvent (8.2 to 41.8 mg/mL) and concentrations of potassium 2-ethylhexanoate (0.2 to 1.2 molar) were also selected using CCRD. From these results, precipitation conditions were selected and applied to the purification of CA from the fermentation broth, obtaining a yield of 72.37%.

Clavulanic acid (CA) is a potent inhibitor of beta-lactamases, enzymes that are responsible for the hydrolysis of beta-lactam antibiotics. It is a secondary metabolite produced by the filamentous aerobic bacterium Streptomyces clavuligerus in submerged cultivations. In the present work clavulanic acid production in batch, fed-batch and continuous bioreactors was studied with the objective of increasing productivity. The operating conditions: temperature, aeration and agitation, were the same in all cases, 28º C, 0.5 vvm and 800 rpm, respectively. The CA concentration obtained in the fed-batch culture, 404 mg L-1, was ca twice the value obtained in the batch culture, 194 mg L-1, while 293 mg L-1 was obtained in the continuous culture. The highest productivity was obtained in the continuous cultivation, 10.6 mg L-1 h-1, as compared with 8.8 mg L-1 h-1 in the fed-batch process and 3.5 mg L-1 h-1 in the batch process, suggesting that continuous culture of Streptomyces clavuligerus is a promising strategy for clavulanic acid production.

We have extended the Dirac-Hartree-Bogoliubov (DHB) approximation developed in a previous work [1] with the inclusion of blocking terms in order to study the pairing properties of both even and odd nuclei. We have concentrated our attention in the isotope chains of 12-26O, 34-56Ca, 48-78Ni and 100-132Sn as well as on the alpha-decay of the new superheavy element (277)112.