ENCIMSKO KATALIZIRANA SINTEZA ESTROV MAŠČOBNIH KISLIN Z IMOBILIZIRANO LIPAZO B IZ CANDIDA ANTARCTICA V ETIL METIL KETONU IN SUPERKRITIČNEM OGLJIKOVEM DIOKSIDU - Krivec, Maja (M. Krivec, 2011)
V zadnjih 20 letih zanimanje za encimsko katalizirano sintezo estrov kot so sladkorni estri, narašča, saj je uporaba večine kemijsko sintetiziranih produktov omejena, zaradi številnih problemov povezanih z načinom proizvodnje. Namen diplomske naloge je bil sintetizirati sladkorne estre maščobnih kislin, ki jih uporabljamo v kozmetični, prehrambeni in farmacevtski industriji. Osredotočili smo se predvsem na sintezo saharoze monopalmitata. Za primerjavo smo izvedli tudi sintezo fruktoze in glukoze palmitata. Encimsko katalizirano sintezo sladkornih estrov maščobnih kislin smo izvedli v etil metil ketonu pri atmosferskem tlaku ter v mešalnem šaržnem reaktorju v superkritičnem ogljikovem dioksidu. Reakcije smo katalizirali z imobilizirano lipazo B iz Candida antarctica. V superkritičnem ogljikovem dioksidu smo izvedli reakcijo sinteze saharoze palmitata in dobili produkt − monoester, ki ni vseboval sledov topila. V primerjavi z organskim topilom, etil metil ketonom, poteka reakcija v superkritičnem ogljikovem dioksidu brez prisotnosti molekularnih sit, kar predstavlja nižje stroške proizvodnje. Višje presnove so bile dosežene kadar smo sinteze izvajali v superkritičnem ogljikovem dioksidu. Over the past 20 years the interest in the enzyme catalyzed synthesis of esthers such as sugar esthers, is increasing as the use of most chemically synthesized products is limited, because of many problems related to the production method. The purpose of this study was to synthesize sugar esters of fatty acids used in cosmetics, food and pharmaceutical industries. Our focus was mainly on the synthesis of sucrose monopalmitate. For comparison the synthesis of fructose and glucose palmitate were also carried out. Enzyme catalyzed synthesis of sugar esthers of fatty acids was carried out in ethyl methyl kethon at atmospheric pressure and in stirred batch reactor in supercritical carbon dioxide. Reactions were catalyzed by immobilized lipase B from Candida Antarctica. In supercritical carbon dioxide a reaction of synthesis of sucrose palmitate was carried out and product obtained − monoester, which did not contain traces of any solvents. In comparison with organic solvent, methyl ethyl kethone, a reaction in supercritical carbon dioxide is proceeding without the presence of molecular sieves, which represents a lower cost of production. Higher metabolism were obtained when we performed the synthesis in supercritical carbon dioxide.