In chemistry and biology a
disulfide refers to a
functional group with the general structure
R–S–S–R. The linkage is also called an
SS-bond or a
disulfide bridge and is usually derived by the coupling of two
thiol groups. In formal terms, the connection is a
persulfide, in analogy to its
congener,
peroxide (
R–O–O–R), but this terminology is rarely used, except in reference to hydrodisulfides (
R–S–S–H or
H–S–S–H compounds).