In chemistry, a<unk>  is a single covalent<unk>  derived from the coupling of thiol groups.  The linkage is also called an SS-bond or<unk>  bridge.  The overall connectivity is therefore C-S-S-C.  The terminology is almost exclusively used in biochemistry, bioinorganic and bioorganic chemistry.  Formally the connection is called a persulfide, in analogy to its congener, a peroxide (R-O-O-R), but this terminology is rare.
Three sulfur atoms singly<unk> ed in a sequence are sometimes called a trisulfide<unk> , although there are in fact two<unk> s.<unk> s are usually formed from the oxidation of sulfhydryl (-SH) groups, as depicted formally in Figure 1.
Disulfide bond
Covalent bond
Glycosidic bond
Carbon-carbon bond
Cyclohexane conformation
Van der Waals strain
Methyl group
Peptide sequence