Application of high performance anion exchange chromatography to study invertase-catalysed hydrolysis of sucrose and formation of intermediate fructan products

Baker's yeast invertase was found to catalyse transfructosylation reactions in aqueous and anhydrous organic media with sucrose as a substrate, leadin g to the formation of five intermediate fructans in addition to the release of D-glucose (D-Glc)and D-fructose (D-Fru). Ail the reaction products were separated and quantitatively estimated using high performance anion exchan ge-pulsed amperometric detection equipment. The unknown products were subse quently identified by linkage analysis as beta -D-Fru-(2 --> 1)-beta -D-Fru -(2 --> 1)-alpha -D-glucopyranoside (1-kestose), beta -D-Fru-(2 --> 6)-alph a -D-glucopyranoside (6-beta -fructofuranosylglucose), beta -D-Fru(2 --> 1) -beta -D-fructofuranoside (inulobiose), beta -D-Fru-(2 --> 6)-beta -D-Fru-( 2 --> 1)-alpha -D-glucopyranoside (6-kestose) and beta -D-Fru-(2 --> 6)-alp ha -D-Glc-(1 --> 2)-beta -D-fructofuranoside (neokestose); and this last wa s eluted together with a disaccharide. The time-course of sucrose hydrolysi s via fructan production in 2 ml of a 50 mM sodium acetate buffer (pH 4.5) containing 0.2 M sucrose and 25 U of invertase was different from that in 2 mi of anhydrous toluene with 1.46 M sucrose and 1,000 U of invertase as a suspended powder. Under the latter experimental conditions, invertase was f ound to exhibit cyclic behaviour, where sucrose was degraded and subsequent ly synthesised. This observation has not yet been reported, as far as we kn ow.