octulosonic acid

oc·tu·lo·son·ic ac·id

(ok'tū-lō-son'ik as'id),
The -onic acid formally formed by oxidation of carbon atom 1 of octulose to a carboxylic acid group; a condensation product of d-arabinose and phosphoenolpyruvate analogous to neuraminic acid. It forms part of the repeating unit of the polysaccharides of the complex lipopolysaccharides of the Enterobacteriaceae constituting the characteristic somatic octose antigens.