Síntese de ésteres derivados de carboidratos com propriedades surfactantes utilizando lipases imobilizadas em suporte sólido

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

Sugar esters constitute one of the main kinds of natural surfactants. These called biosurfactants show different advantages related to the synthetic surfactants. They are easily degraded in the ground and water with low toxicity what allows their industrial use in pharmaceutical food and cosmetic products. A particular strategy about these compounds is that they can be synthesized from renewed subtract sources as carbohydrates and vegetal fatty acids. However, they still not widely used because of the high cost of large-scale production, associate to the inefficient methods of product recovery. Sugar esters can be synthesized by chemical or enzymatic methods. The chemical ester production requires high temperatures and leads to a low selectivity, forming colored pigments as side products. The enzyme application in the ester synthesis leads to regio and stereo selective products. The present work was focused on biosurfactant synthesis using biocatalysis with different carbohydrate, fatty acid and enzyme source. The experimental work was carried out employing different carbohydrates, as sucrose, lactose, glucose, fructose and glucosamina with lauric acid (dodecanoic), capric (decanoic) and caprylic (octanoic). The biocatalyst used were lipases from the microorganism source; Candida rugosa, Aspergillus niger, Rhizopus oryzae, Candida antarctica, Thermomyces lanuginosus and Mucor javanicus. For a better application of enzymes they were immobilized on chrysotile as support. Positive results were found for lauric acid with fructose, sucrose and lactose using lipase from Candida antarctica. The size of carbon chain in the fatty acid molecule suggests that twelve carbon atoms are more efficient for the acilation of carbohydrate as already seen in the literature. The identification of reaction product was done by infrared spectroscopy showing the characteristic band around 1740 cm-1. No idea about the right position of carbohydrate acylation was found. Wherever, according to the literature for analogue systems, some hypothetical structures for de products are suggested. These method show good possibilities of carbohydrate acylation using lipases from Candida antarctica with twelve chain fatty acid molecules

ASSUNTO(S)

enzymatic acylation lipases biosurfactant biossurfactantes acilação enzimática lipases quimica

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