Kinetics of the synthesis of lactose molecular compounds

We studied the molecular compounds 5 alpha/3 beta-lactose and 3 alpha-/2 beta-lactose, which are due to the physical and chemical association of the two anomeric forms alpha- and beta-lactose. The kinetic parameters of the synthesis were determined: the order of the reaction, the rate constant, and the energy of activation. A nondestructive method employing X-ray diffraction was used for the quantification of lactose in the solid state. The synthesis of 5 alpha-/3 beta-lactose was almost three times faster than that for 3 alpha-/2 beta-lactose. Furthermore, the activation energy for the synthesis of 3 alpha-/2 beta-lactose was twice as high as that for 5 alpha-/3 beta-lactose. The observed differences could be explained by different synthesis pathways.