The present invention relates to a method of preparing an oligosaccharide composition, said method comprising the steps of:(a) providing a pectin and(b) performing, in any order, conversion of carboxylic acid groups to the corresponding alcohols and cleavage of glycosidic bonds under conditions suitable to give an oligosaccharide composition.The present invention also relates to an oligosaccharide composition obtainable or being obtained by using such a method of preparing an oligosaccharide composition.The present invention further relates to a method of preparing a coupling product of an oligosaccharide composition.The present invention is also directed to a coupling product of an oligosaccharide composition.The present invention also relates to pharmaceutical compositions comprising the oligosaccharide composition or the coupling product of an oligosaccharide composition as well as medical uses and diagnostic uses.
