Thermo-kinetics of lipase-catalyzed synthesis of 6-O-glucosyldecanoate

Thermo-chemical energy assessment for production of energy-rich fuel additive compounds by using levulinic acid and immobilized lipase

“…The smaller the ΔH # -value, the lower the amounts of energy needed for elongation and compression of the chemical bonds to attain the transition state or the activated complex [29]. Moreover, positive sign of the ΔH # -value indicated endothermic nature of the present reaction system [29,32,33]. Thus, lower ΔH # value in MTBE solvent was attributed to ease of formation of enzyme-substrate complex because of the more flexible enzyme conformation in a hydrophobic etheric solvent [34].…”

“…This observation suggested more spontaneous break-down of activated enzyme-substrate complex into the product [26,32,34,35]. In context to this, the polar solvent possesses more ΔG # -value as compared to non-polar solvents which accounted for less feasibility of the reaction in the polar solvent [29,[32][33][34][35].…”

“…However, potential applications of other levulinates (Table 2, entries 3, 5-8) need to be investigated as a fuel/diesel blend compound which still finds the great scope in research to explore. The EA and ΔH # value decrease from the methyl to butyl levulinate synthesis, which was attributed to the decrease in polarity with the increase in alkyl chain (Table 3) [26,33]. Since, more polar reactant pulls the essential trace amount of water from the pockets of enzyme and destabilizes the enzyme conformation [15].…”

“…The lower enthalpy of activation (ΔH # -value) indicated easy formation of the enzyme-substrate complex, while higher ΔH # -value indicated complexity in the enzyme-substrate complex formation [29,32,33]. The smaller the ΔH # -value, the lower the amounts of energy needed for elongation and compression of the chemical bonds to attain the transition state or the activated complex [29].…”

High-yield synthesis of bioactive ethyl cinnamate by enzymatic esterification of cinnamic acid

“…Moreover, water is a product of this reaction, which has clear thermodynamics effects on yields. Thermodynamic water activity (a w ), as an important parameter, is often used to evaluate the effects of water on enzymatic reactions in organic media (Gumel, Annuar, Heidelberg, & Chisti, 2011). Fig.…”