The total synthesis of TMG-chitotriomycin using an automated electrochemical synthesizer for the assembly of carbohydrate building blocks is demonstrated. We have successfully prepared a precursor of TMG-chitotriomycin, which is a structurally-pure tetrasaccharide with typical protecting groups, through the methodology of automated electrochemical solution-phase synthesis developed by us. The synthesis of structurally well-defined TMG-chitotriomycin has been accomplished in 10-steps from a disaccharide building block.

Chondroitin sulfate (CS), a type of glycosaminoglycan (GAG), is a factor involved in the suppression of myogenic differentiation. CS comprises two repeating sugars and has different subtypes depending on the position and number of bonded sulfate groups. However, the effect of each subtype on myogenic differentiation remains unclear. In this study, we spiked cultures of C2C12 myoblasts, cells which are capable of undergoing skeletal muscle differentiation, with one of five types of CS (CS-A, -B, -C, -D, or -E) and induced differentiation over a fixed time. After immunostaining of the formed myotubes with an anti-MHC antibody, we counted the number of nuclei in the myotubes and then calculated the fusion index (FI) as a measure of myotube differentiation. The FI values of all the CS-treated groups were lower than the FI value of the control group, especially the group treated with CS-E, which displayed notable suppression of myotube formation. To confirm that the sugar chain in CS-E is important in the suppression of differentiation, chondroitinase ABC (ChABC), which catabolizes CS, was added to the media. The addition of ChABC led to the degradation of CS-E, and neutralized the suppression of myotube formation by CS-E. Collectively, it can be concluded that the degree of suppression of differentiation depends on the subtype of CS and that CS-E strongly suppresses myogenic differentiation. We conclude that the CS sugar chain has inhibitory action against myoblast cell fusion.

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Glycosaminoglycans (GAGs) are found in the various tissues and are involved in many physiological functions. Since the rhesus monkey (Macaca mulatta) is the most widely used nonhuman primate in biomedical research, an understanding of the compositions of GAGs in their tissues is important. The aim of the study was to determine the content and sulfation pattern of disaccharides contained in several tissues of the rhesus monkey. The chondroitin sulfate (CS)/dermatan sulfate (DS) hybrid chain was extracted from several tissues of female and male rhesus monkeys. Compositional analysis was performed after digestion with chondroitinases ABC and ACI to reveal the sulfation pattern of the CS/DS hybrid chain. This study revealed that the major CS/DS disaccharide units present in the tissues were A- and C-types. The E- and iE-types were specifically distributed not only in the tracheal tissue but also in gastrointestinal tissues.