Milk Oligosaccharides: Structural Characterization and Future Aspects

Abstract

Milk oligosaccharides are a variety of free saccharides which are found in milk/colostrum along with lactose, and have a lactose unit at their reducing ends. Human milk contains about 7% of carbohydrate of which around 20% consists of more than 100 milk oligosaccharides. Detailed structural studies of human milk oligosaccharides were started by Richard Kuhn during the 1950s, followed by those of Montreuil et al., Kobata et al., Egge et al., Strecker et al., Gronberg et al. and Kitagawa et al., etc. At least 93 human milk oligosaccharides have been characterized up to date (Urashima et al. 1997). Nonhuman milk oligosaccharides have been studied by Kuhn et al., Messer et al., and Urashima et al., etc., and more than 100 oligosaccharides were characterized in milk or colostrum of brown capuchin, buffalo, horse, cow, goat, sheep, Ezo brown bear, Japanese black bear, polar bear, whitenosed-coati, elephant, rat, dog, beluga, Minke whale, giant panda, crabeater seal, hooded seal, bearded seal, harbor seal, mink, bottlenose dolphin, echidna, platypus, and tammar wallaby (Urashima et al. 2001).