Determination of Sialyl and Neutral Oligosaccharide Levels in Transition and Mature Milks of Samoan Women, Using Anthranilic Derivatization Followed by Reverse Phase High Performance Liquid Chromatography

An improved analytical method using reverse-phase high performance liquid chromatography following anthranilic acid derivatization for the measurement of each oligosaccharide level in transition (5 to 10 d lactation) and mature (21 to 155 d lactation) milks of sixteen Samoan women is described. The method was applied for the measurement of sialyl as well as neutral oligosaccharide levels. We found that disialyllacto-N-tetraose (DSLNT), sialylacto-N-tetraose c (LSTc), and 6'-sialyllactose (6'-SL) were the most abundant of the sialyl oligosaccharides. In the neutral oligosaccharide fraction, lacto-N-fucopentaose II and III combined (LNFP II+III) were the most dominant, followed by lacto-N-tetraose (LNT) and 3-fucosyllactose (3-FL). 2'-Fucosyllactose (2'-FL) and lacto-N-fucopentaose I (LNFP I) were absent in some and found at low levels in most of the Samoan women. Our study indicates that the milk oligosaccharide composition in Samoan women is similar to that of Japanese women with respect to sialyl but not to neutral oligosaccharides. The differences in neutral oligosaccharides might have a genetic origin.