Homocystine

Names
IUPAC name (2S,2′S)-4,4'-Disulfanediylbis(2-aminobutanoic acid)
Other names L-Homocystine; L-4,4′-Dithiobis(2-aminobutanoic acid)
Identifiers
CAS Number	626-72-2 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:141698
ECHA InfoCard	100.009.966
PubChem CID	439579
UNII	804AS222UE Y
InChI InChI=1S/C8H16N2O4S2/c9-5(7(11)12)1-3-15-16-4-2-6(10)8(13)14/h5-6H,1-4,9-10H2,(H,11,12)(H,13,14)/t5-,6-/m0/s1 Key: ZTVZLYBCZNMWCF-WDSKDSINSA-N
SMILES C(CSSCC[C@@H](C(=O)O)N)[C@@H](C(=O)O)N
Properties
Chemical formula	C8H16N2O4S2
Molar mass	268.35 g·mol−1
Appearance	colorless solid
Melting point	281–284 °C (538–543 °F; 554–557 K)[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Homocystine is the organosulfur compound with the formula (HO₂CCH(NH₂)CH₂CH₂S)₂. It is disulfide derived from oxidation of homocysteine.^[2] Its relationship with homocysteine is analogous to the relationship between cystine and cysteine.