The thiobarbituric acid assay of sialic acids.

Members of the sialic acid family of compounds occur in a variety of tissues and body fluids (la, 2) and in bacteria (3), incorporated in conjugated protein. The naturally occurring sinlic acids are substituted neuraminic acid derivatives (Nacetyl, N-glycolyl, N, 0-diacetylneuraminic acid). These are collectively termed “sialic acids.” The unsubstituted 9 carbon chain is called neuraminic acid (4) (Scheme 1).