Study on the alcoholysis of isoflavone catalyzed by ionic liquids

Abstract

Alcoholysis of soybean isoflavone glucosides by butanol catalyzed by acidic ionic liquids was studied. The effects of the ionic liquid catalyst type, catalyst concentration, reaction time and reaction temperature on glycoside conversions, and aglycons yields were investigated. The optimum reaction conditions are found to be as follows: 0.036 g mL -1 of ionic liquid [BIM]HSO 4 as catalyst, reaction temperature at 104±1ºC, reaction time of 100 min. Under these optimum reaction conditions near complete conversions of the three kinds of glycosides (daidzin, glycitin and genistin) are obtained. Furthermore, the kinetics parameters for the alcoholysis were estimated. The activation energies of alcoholysis for the three kinds of isoflavone glucosides are 124 kJ mol -1 , 67 kJ mol -1 and 115 kJ mol -1 , respectively.

Reactivity of Brönsted acid ionic liquids as dual solvent and catalyst for Fischer esterifications

“…358 K, 6 hrs, N2 [20,26] as well as our former work [28]. However, when water-immiscible acid or alcohol is used as reactant, the hydrophobic group in the ionic liquids will contribute to the miscibility between reactants and catalyst, which may increase the reactivity of the catalyst.…”

“…Fig. 1) were synthesized according to our previous work [28,29] and literatures [17,30]. The residual water contents of all the five ionic liquids were determined by Karl Fischer Titrator (ZKF-1) to be less than 2%.…”