Human proinsulin, the single-chain peptide precursor of insulin, consists of the insulin A and B chains connected by the 31 amino acid C-peptide. Cleavage of proinsulin by proteolytic enzymes produces insulin and free C-peptide.

Sevelamer carbonate is a non-absorbed phosphate binding crosslinked polymer, with the same polymeric structure as sevelamer hydrochloride, in which carbonate replaces chloride as the counterion.

(-)-Guaiol is a biocatalyst.