嘧啶是杂环、六元、含氮碳环结构，尿嘧啶、胞嘧啶和胸腺嘧啶是含核糖核苷（分别为尿苷、胞苷和胸苷）或含脱氧核糖的脱氧核苷及其相应核糖核苷酸的基本结构或脱氧核糖核苷酸。

C-Peptide, dog is a component of proinsulin, released from pancreatic beta cells into blood together with insulin. The C-peptide of proinsulin is important for the biosynthesis of insulin but has for a long time been considered to be biologically inert.

用作有机合成及医药中间体。