the chemical structure of the k52 antigenic capsular polysaccharide ( k52 antigen ) of escherichia coli o4 : k52 : h- was elucidated by composition , nuclear magnetic resonance spectroscopy , methylation , periodate oxidation before and after graded acid hydrolysis and by oligosaccharide analysis .
C0032594
polysaccharide
C0028959
oligosaccharide